There are two different fuel starvation things happening with the LLY's:

1) P1093 - This causes the truck limp, sets a code, but makes full power up to 2000 rpm where the limp-limiter kicks in. It is unpredictable except that it happens during acceleration, and some tunes do it more than others. The second you reset it, it recovers. It can happen immediately on hitting the throttle.

2) Laying down - This throws no codes, I checked. It happens only after about 8-10 seconds of hard acceleration. It reduces the power down to about stock HP levels, and takes the engine about 15 seconds to recover. It is not predictable, and when it happens, the power falls to the same level every time.

On cause 2, it is like something is collapsing then taking awhile to relax. Or like the fuel filter is full of air, and needs time to fill back up.

I guess "why" it's happening is not important if lift pumps fix it. But the symptoms would point to a "weak link" in the fuel system. Some component is failing at semi-random times. Perhaps air leak in the filter assy, a hose collapsing, or something else.

I had it for the first time while on a dyno. It would have been a 530'ish pull, stack with n2o. I have 2 pulls with, and without the laydown and the same basic setup. TQ peak happens at ~2800 with this setup. At 2700 both setups make the same power, then instead of continuing to climb, the laydown pull just levels out, then falls. It didn't cough, throw a code, or give any other indication, just fell down.

Why would you starve one time, and not the other? It makes no sense if it is classic fuel starvation. On a gasser, it would happen every time at the same point when the float bowl drained. Why doesn't it recover quicker? It certainly would be easier to figure out if it was consistent, but it is not.

McRat,

We observed the laying down phenomenon at Kennedy's Dyno Day. Basically it appeared that the computer had some sort of torque management built in, similar to your Vette. As soon as the engine went above approx. 680 ftlbs on the dyno something would pull it back down to 680 (defuel?) and then flat line at 680 the rest of the pull. We saw this happen with multiple manufacturers boxes. You could fuel the motor real hard in the begining and it would exceed the magic 680# but only for a brief second and then it would get pulled back down. It seems like load on the engine would play a big part in when this was triggered, perhaps an inertia test on a dyno with a real light roller rather than a load test would keep the (defuel?) from getting triggered? Perhaps it is inherent in different software flashes from GM as to why some trucks do it and others don't.

Fascinating stuff! :D Well, from a research point of view. Sucks from a go fast point of view. :(

You LLY guys have us LB7 guys really worried with your 45 psi boost reports and not blowing up turbos. :confused:

....... So, would that be an Allison or PCM reflash?

Nobody knows if it will blow up the turbo yet.:eek: But at least I have witnesses now. I AM NOT CRAZY!!! :D

Or do we know if the efficiency of the turbo limits the power. We do know that at 3200 RPM, with a 440rwhp tune, the HP is still climbing which may indicate the LLY turbo might flow better than the LB7. First LLY with injectors will find out for sure. Expensive experiment though.

If the brain is shutting it down, would it not be possible to see that in the injector pulse width? It would certainly take some fiddling, but if you really wanted to know for sure, get someone with a oscilloscope and watch the pulse width of the signal.

Rat, does it coincide with fuel rail pressure as observed on a Tech II?

I haven't had a Tech II on the truck during laydown yet. If the ECM did it, you'd see it in commanded vane position, commanded rail pressure, and injector pulse width reduction. If GM is doing it, they would make it "smooth" I would think.

I don't think GM is intentionally doing it though. Why? It is erratic in nature. You can do 5 1/4mi passes, Laydown, Full Power, Full Power, Laydown, Full Power. If it was GM doing it intentionally, once it saw the same conditions on the sensors, it would react the same every time.

It might be accidental though. All software has bugs, and cars are no exception.

I really need to buy a Tech II and am taking donations now. ;)

.......... AIR?............ Has an LLY *with* a liftpump seen this occurance?

Yes, a lift pump should fix it.

But my guess is that it has nothing to do with the cause for the laying down.

Pat, I thought u had a techII at the dyno day.
Or did it leave before u rolled?

It was the first time it laid down on the dyno. Wasn't expecting it, or we could have monitored the engine values when it happened.

mcrat, have you stacked the edge and predator yet?

The Predator Edge stack did not work for me when I tried it. The truck refused to get rolling off the line and took too long to shift. The Predator by itself ran much quicker.

Your results may vary, some people say they had good luck with that stack.

it stacks "ok" with me, somewhat slow shifts (stock trans) but i get some bucking, have any of your stacks done this, im trying to figure out if its the stack or lack of fuel

So far the "bucking" during shifts on mine is pretty much Edge specific. A couple of other tuners have done it slightly during trans learn, but the with the Edge it did not go away. A new version is coming out soon to address the bark.

It will do it at the lower power levels even, stacked or not. Do a search on "Turbo Bark".

I think I might of had the same thing happen to me this weekend, I'm going down the track then all of a sudden there is no power, no codes then shut the truck off then powers back.

About 1/2 track? Power reduces about 50% for the rest of the pass? Did it happen every pass?

Just want to know more about this, Got SCIII and 4" straight pipe installed when it happened to me. Getting on interstate,level 5 , punched it and after a few seconds truck just bogged down, no go past 2k rpms, I gave it moderate accelaration and it just caughed. Pulled over, cycled key several times and all was fine. Has happened 3 more times since then, only when I'm really on it. Any more info?

You got the P1093. The ECM controls how much fuel rail pressure is needed (Commanded Pressure) and it looks at the fuel rail pressure sensor. If the commanded pressure does not match the actual pressure by a certain amount, it assumes there is a fuel leak somewhere or a bad fuel pump, and tries to protect you by going into Limp Home Mode. Limp Home limits your RPM to 2000. It can be reset with a code reader while you drive, or as you found out, after a number of successful startup cycles.

Some tuners do it more often than others. Dirty fuel filters will do it, as will a failing "fuel rail fuel return solenoid"? which is in charge of dumping extra fuel back into the tank.

so......you think a lift pump will help solve this?

As soon as I can get my tank down some more (1/2 a tank right now), I'm first going to try a different fuel pickup, and then a liftpump.

Will it work? Magu made big HP last week, and he's running a pump.

After talking with Charles Ekstam (Fuel Preporator, Airdog) it sounds like this is going to be the key. According to him, an Airdog or lift pump will probably solve the problem, but he believes (as do I) the big problem is in the pickup.

I take it Magu is no longer throwing the 1093?

Will be waiting to hear more

McRat is correct, no longer getting P1093 after FASS.

Previously, could pretty much get it at will usually on a "pi$$ed off pass", the 35 MPH sightseer in front of me that wouldn't move over....by imitating that, could generate 2 out of three times.

Magu- Does it feel much stronger on the big end now? Is the "flat spot" gone when running WOT?

I will be doing an Airdog later on this week and most likely dropping the tank and doing a custom pickup. Time to get rid of the 1093 once and for all.

Haven't been able to get a real run yet, what I have done pulls until I shut down....
March 25 will be doing test and tune on 1/4 mile track, April 3 will be bracket racing...should get a lot of new info from those days.

If you guys use the Trippin pick-up in the tank, I would not use a lift pump that returns into the filler neck. You will have issues.
mike

Issues?

Issues?
OK, you will have problems with fuel delivery with a lift pump that returns fuel via an external fuel return line to the tank. This means all the Preporator products and FASS pumps have the problem and they have been made well aware of it about a year ago.

what if you plumb the external return to a "t" in the pump inlet?

As soon as I can get my tank down some more (1/2 a tank right now), I'm first going to try a different fuel pickup, and then a liftpump.

Will it work? Magu made big HP last week, and he's running a pump.Pat, What kind of fuel pickup are you thinking of, I changed my stock tank out this weekend for a 66 gal Super tank and don't think much of that stock fuel pickup. I have tossed tha 1093 3x now after a WOT pass on the highway, and then wham- limp Censored mode. Went to the dealer and I can do it with a 1/4 tank of fuel most any
W
O
T take off, the tech was :eek: surprised to say the least and that was chiped and no chip, It won't do it so far no chip if the tank is over 3/4 (stock tank). He's going to get a tech for the weekend and go play with me- dmax kinda guy):h , to see what it will show realtime.

I'm going to run the Trippin pickup. Nice piece. Now that I got back from Texas...

I STILL HAVE 1/2 a tank!!! :mad: Guess it's mostly downhill from AZ, so didn't use much fuel going home from AZ.

DieselTech- What fuel delivery problems are you referring to? Are these problems limited to the Dmax or all diesels?

Yeah it would be interesting to here what the problem is? I understand the return fuel dumps into the filler neck. This causes problems for those that leave there vehicle running while filling up.

What other problems does it cause?

The people that are currently using these systems without problems, what have they done to work around these problems?

I can see how returning the air bubbles back into the tank may cause problems if the tank is really low, but other than this what are the issues?

The reason I ask if its limited to other makes is because we have not found any problems with Cummins or Powerstrokes yet.............as far as fuel returns go.

Yeah it would be interesting to here what the problem is? I understand the return fuel dumps into the filler neck. This causes problems for those that leave there vehicle running while filling up.

What other problems does it cause?

The people that are currently using these systems without problems, what have they done to work around these problems?
You might want to talk with Diesel 5 about the problem as he had it until he got rid of the FASS and the Airdog did the same thing. I have had several calls from the Dodge guys and they are having it too so I guess DSTRBD hasn't sold many or talked/listened to many customers. I personally called both FASS and Preporator over a year ago and told them about the problem. Talk with Preporator about 3 months back and Charlie said he was aware of the problem but did not have a fix for it. He also confirmed the problem with both the Dodge and GM but I did not ask about the Furd's. Bottom line is it is a design flaw in the way they made their systems work and there is nothing they can do to resolve it without a redesign. :eek:

If it is a return issue, the filler neck on the lly is tight, what is wrong with a tube/hose drop in the tank with the factory return or is the whole unit replaced,? The new super tank I installed would have a pre drilled/taped hole for a return, but looking at the factory tank you could drill and tap that with the use of a locking nut on the interior and be good to go I think. I have not seen what Trippins device looks like so I am shooting in the dark here, just a thought.

Get a return pump and run the tube as deep as possible. ...... See J/K's new pump?

Get a return pump and run the tube as deep as possible. ...... See J/K's new pump?
Richard, that won't work. I am the one that did all the fuel pump experimenting on Davids ( DIESEL 5) truck. I am the one that flatbedded his truck back to the shop when the new pump quit. Do not run a fuel pump that will not feed fuel if it takes a dump. DIESEL 5 is now running twin FM 100s and they work fine and dandy with Trippins pick up. No more stalling when the fuel tank gets below half. I know now exactly which fuel pump I will be using in my truck. It is being tested right now and almost ready .
mike

Dieseltech- No, I have not dealt with nor talked to many Cummins guys, but the Powerstrokes are running great with them. Thanks for the personal attack though, shows alot about your character. Careful how you talk to people, never really know who it is on the other side. You still have not defined the problem though.

10-4... I thought the problem lay in a different area. I wasn't aware or did not precieve the pick-up fuelpump it's self dieing. I thought that this was in refrence to the return "bubbling" and creating an 'air lock' right off the tank. ....................... I would not want a pump that did not bypass, either.

Yeah it would be interesting to here what the problem is? I understand the return fuel dumps into the filler neck. This causes problems for those that leave there vehicle running while filling up.

What other problems does it cause?

The people that are currently using these systems without problems, what have they done to work around these problems?Bronco,

My truck would stall when fuel level droped below half a tank, so I had to keep the tank full at all times which was a real PITA.
Mike L tried a total of three lift pumps on my truck and all had similiar issues.
The last L/P just quit on a the 405 FWY in rush hour traffic Censored . I was very surprised because the pump was only a couple of months old :confused: .
I am running the twin FM-100's + Trippin's fuel p/u and I am very pleased :) .

Dieseltech- No, I have not dealt with nor talked to many Cummins guys, but the Powerstrokes are running great with them. Thanks for the personal attack though, shows alot about your character. Careful how you talk to people, never really know who it is on the other side. You still have not defined the problem though.I know who you are so no worry. Why would I tell you since you seem to know everything all ready. As far as a personal attack maybe you should think of that the next time you jump into a discussion that you know little to nothing about and try to mislead people. I told the truth so if that hurts you so be it. What I will tell you is the same problem occurs with a stock pickup as well. The problem is greater with the improved pickup. Before you stick your foot in your mouth again it might be wise to at least know what your talking about!

On edit
I see you have gone back and edited your orginal post and now say you have no trouble on Ford's. This is a Duramax site so why bring Ford's up here. I believe this is the line you have used in the past!

I am running the twin FM-100's + Trippin's fuel p/u and I am very pleased :) .
I am running the same set up except I dont have the trippin PU.

No return or bypass. Easy plumbing and it gets the job done. I can run as low as i dare(Never take my truck lower than a 1/4 so I dont know what would happen there?) and not worry about fuel starvation.

Nate, trust Steve. If you want to run a trippin PU and an airdog or the like and have its bypass puking into the filler neck I am willing to bet you will have issues. He and others have already found this out. I dont think airdog and fass even has a Duramax to test on, let alone the stuff we are doing. I dont think they know **** in this aspect.

Bronco,

My truck would stall when fuel level droped below half a tank, so I had to keep the tank full at all times which was a real PITA.

Nobody wants to keep there tank 1/2 full. Ecspecially me, I try and run to the yellow light every time. I try to burn off the water and junk to avoid any buildup.

So is this isolated or does, Trippin, Diesel Power,Dmax Doug, and the others all have to keep there tank 1/2 full or more?

What is the actual problem from a mechanical point. Pickuptube filling with air and vapor locking?

Dieseltech....easy bro....DSTRBD was just trying to help. This is starting to become like something out of the TDR nightmares. Everybody has made mistakes before and I don't think any of this was meant to mislead anybody....sheeesh!

Nate, trust Steve. If you want to run a trippin PU and an airdog or the like and have its bypass puking into the filler neck I am willing to bet you will have issues. He and others have already found this out. I dont think airdog and fass even has a Duramax to test on, let alone the stuff we are doing. I dont think they know **** in this aspect.
FASS has a few D-max trucks around this area that are running FASS systems. I dont think any of them are running a trippin PU. What type of issue are you guys referring to with the trippin PU and a FASS?

Dieseltech....easy bro....DSTRBD was just trying to help. This is starting to become like something out of the TDR nightmares. Everybody has made mistakes before and I don't think any of this was meant to mislead anybody....sheeesh!
Well I guess after him jumping in, more than a few times when he doesn't know what he is talking about I've had enough. It is my opinon he has been misleading people and it's time for it to stop. If he would like to learn that's great but to just put statments up to push sales then when he gets called on it he edits his post is not right. There is a problem here and members here have had it both with and witout the modified pickup, but yet he said that there is no problem.

I am doing my best to translate Kalifornian into English.

Let me see if I understand the hints Mike L and DieselTech have shared.

When using either a Fass or Preporator with 1/2 tank of fuel or less, your truck may stall. This is because the pickup tube sucks in air and vapor locks.

This happens on trucks with stock pickup tubes and also modifyed pick tubes.

So a few questions I still have.

Does this have anything to do with the programming installed?

Does this happen to everybody that uses these products?

How frequently does this happen?

I am very suprised that so many have these products in there signatures but yet no one has ever mentioned a problem before. Was it because they did not put 2n2 together or because they did not want to admit a 700.00 dollar product was causing problems or it because very few people have actually had these problems?

The sooner people start fessing up real info. the better off we will all be.

If we cannot share product concerns then what good is this forum other than another forum of modern day marketing?

When you fill your truck up at the Diesel pump the fuel going down the filler neck hits the fuel in the tank, splashes around and foams.........

Foamy fuel is full of air...........

Air filled fuel is no good..........

So returning fuel to the tank via the filler neck might seem like a novel idea but it does not quite get the job done....

Why do you think the stock pickup returns the fuel the way it does........maybe GM knows something........

Just an observation...............

Notice the return line goes to the bottom of the tank,returning the fuel at the bottom of the tank in fuel instead of dumping it down from the top of the tank via the filler neck.

See..............

http://www.socaldiesel.com/newpump.jpg

The problem is very simple when you take the time to look into it. Most modern day fuel tanks are plastic. Becuase of this there are no baffles in the tanks like the old days so the manufactures have made the pickup assemble work as a pickup and a baffle. They contain a can about 1 quart in size with the pickup inside of it. This one quart area holds the fuel at the pickup when the tank is below about 1/2 tank. As the system pulls fuel the can/will get low on fuel. There are one way valves install on the can that allow fuel to be drawen in but as soon as air hits the valve it closes. These valves are small so fuel enters at a slow rate. The Preporator/Fass systems pull large amounts of fuel out all the time and return it back to the tank outside the pickup can. This causes the can to run empty and allows the pickup to suck air into the fuel system. The foaming fuel from the return line of the Preporator/Fass entering the fillter neck cause event more air to enter the fuel because of the fuel dropping into the tank. The stock system does not do this. The larger pickup just allows the pump to empty the can faster but since they already empty it stock it doesn't much matter. A properly design fuel system will not have this problem.

So the picture from GMC-20002-Dmax, that sits down inside a can with once way valves?

How hard is to desing a retun line that dumps into this can?

Or is easyer to just regualate vlotage tot he pump?

Designing pieces is easy for some of us but is it not up to the parts manufacture to design the systems they sell, so that it works right in the first place? This problem was not created by the new fuel pickup, it's just made it worse by allowing the free flow of fuel. If the Preporator/FASS system works as advertised you will be pushing all the air they claim to remove right into the pickup if you returned it into the can.

The point Diesel Tech is making is that the fuel tank is unbaffled.......meaning the fuel is free to slosh around..........Gm is using an area in the tank to capture fuel and return that fuel to the same location.........via the stock return line in the stock sending unit, therefore you keep the can or resevoir full most of the time.........the FASS sucks it dry especially with the more effecient fuel pick-up......

By sucking the fuel out quicker and not returning it a way that helps to keep the little can or resevoir full is the problem.........it is the design.......

The stock pick-up returns the fuel in exactly the same location it draws from........BY DESIGN

That was my point and the reason I posted Trippins PIC from his web site.

T;) NY

If the "can" actually can be emptied at high #2 HP level, could this be the "Reason #2" for the LLY laydown at 1/2 track?

Do longbeds have more issues than shortbeds ???????

:cool:

So the system was designed around X amount of flow because of Y amount of HP.

So when a huge tune is installed, can the fuel demand from the factory vacum pump suck this can dry?

Bronco

Looks like you have testing to do!

I guess when I drop my tank, I had better give myself a few days for R&D.

Simplest diagnostic would be to put a 5 gallon can in the bed, and run the fuel line to it.

I think I'm going to do that. :D

Simplest diagnostic would be to put a 5 gallon can in the bed, and run the fuel line to it.

I think I'm going to do that. :D
Pat
I did that with both fuel pumps. I did not like the bubbles in the 5 gal. bucket from the return hose. Remember there are no problems as long as the fuel level stays above the bucket because it cannot be sucked dry. At half level and below the truck would hesitate or die when you came to a sudden stop or go up or down a steep incline. When the level was below quarter the truck often would have to crank a long time befor starting. Also remember that every time you starve the fuel line you sucked air and you must get out and crack the bleeder with the pump running. Problem is when you are below quarter tank and sucked air , bleeding is useless, you are screwed till you put more fuel in the tank. When I bypassed the pump the truck ran great right down to almost empty without a problem.

Ok, can you cut a whole in the bowl? .......er, that's sounds funny. Can you make the check valves bigger or just punch them out?

I think Diesel Tech and Trippin are working on a solution. I don't think drilling the bucket is the answer plus it is plastic and spring loaded; it might crack. These puppys are 400.00 bucks. No room for mistakes.

*http://www.ls1tech.com/forums/images/smilies/LS1Tech/secret.gif (http://www.ls1tech.com/forums/misc.php?do=getsmilies&wysiwyg=0&forumid=5#)

There's a fast little 2wd dmax that has a fuel cell in the bed for racing :grd:

After thinking about all of this for a while, it appears the problem is not really the basket or everybody using any kind of aftermarket pump or pickup would be having these stalling issues.

So it is really the constant ariation of the fuel that is causing the problem. In order for the Fass/Prep to work at low fuel levels a method of returning the fuel without causing the basket to suck air is needed.

Either returning it to the bottom of the tank or attaching some type of valve that insures the air goes up and the fuel goes down would be required?

I always wondered about the constant ariation of the return fuel, but figured the air separator would take care of this problem. Kinda creates its own visous cycle and the trap door comes to save the day.

I am still a little miffed at how come nobody has ever brought this info forward yet? Either this does not happen very often, eveybody keeps there fuel tank full or nobody wanted anybodys feeling( wallets) to get hurt?

After thinking about all of this for a while, it appears the problem is not really the basket or everybody using any kind of aftermarket pump or pickup would be having these stalling issues.
Well I would suggest that you go do a little testing. With out much effort you will see what is going on and I'm sure you will change your thinking as it is incorrect. Simply remove your fuel tank and install a window in the tank. Then connect it back to the truck with a FASS/Preporator connected as per the instructions that come with the unit. Set the fuel level such that it is below the top of the can and watch what happens.

So I guess the basket gets sucked dry as well.

So the other pumps available get away with this because they return there fuel directly to the basket .

You would think sending that much fuel up to the engine and only giving it the factory method of return would cause other problems. I always prefered fuel systems with a regulator/return prior to the engine. Guess this basket kinda screws up that option.

A voltage regulator conneted to the PCM or boost is the only way to go.

A voltage regulator conneted to the PCM or boost is the only way to go.
My thinking as well, something like the old Kenne Bell adjust-a-pump or whatever it was called. Voltage varies with demand. You need to return the fuel to the "can", but perhaps have a air seperator at that point. At full throttle high demand you will not have much fuel being returned due to the engine using it. At low demand, the fuel pump itself would just deliver less fuel, which would also return a lesser amount.

The solution here is keeping the fuel pump supplied with non-aerated fuel at all times at all tank levels.

I wonder if the Airdog 80 cause these problems as well? It flows about 50 GPH less than the 135. So maybe it will not drain the basket?

On the big units, why not just put a T on the clean fuel side and put a little back into the basket? Seems like this would keep the basket full.

Has anyone tested the return pressure on the factory return line? You could just tap into this and run clean fuel right back into the basket via the factory return line. Of course you would have to install a cheap regulator to limit volume and pressure so it did not hamper the factory return flow.

So T into the clean outlet of the 135, go through a 7 dollar regulator and T into the retun line.

This way you have your air separator and also a full a basket. Wonder if this would work?

Simply remove your fuel tank and install a window in the tank.
Or.........take a clear 5 gal fuel container to your favorite fuel station and hold the nozzle wide open until the level reaches the top of the container. Then pause and observe how much fuel and how much foam is in the container.

Now draw a correlation between this and a "Foaminator 2000" lift pump after 10 minutes of driving.

Things that make you go Hmmmmmmmmmmm...........

Well I guess after him jumping in, more than a few times when he doesn't know what he is talking about I've had enough. It is my opinon he has been misleading people and it's time for it to stop. If he would like to learn that's great but to just put statments up to push sales then when he gets called on it he edits his post is not right. There is a problem here and members here have had it both with and witout the modified pickup, but yet he said that there is no problem.
Steve- You obviously have some underlying insecurity issues that you need to get checked out. Dont act like you know me because you dont and for that reason, I am not pissed. However, keep runnin your big mouth and things will change, fast. You may be someone in the performance world, but you arent sh!t to me.

Go ahead and point out where i was misleading people. I am trying to gather info on what others have tried. Seems there is alot of guys with 1093 issues and no definate solutions. I guess you must be getting ready to release your fuel system soon. Easy tiger, everythings gonna be alright.

By the way Steve, I dont even sell the Airdog.

By the way Steve, I dont even sell the Airdog.After talking with Charles Ekstam (Fuel Preporator, Airdog) it sounds like this is going to be the key. According to him, an Airdog or lift pump will probably solve the problem, but he believes (as do I) the big problem is in the pickup. I will be doing an Airdog later on this week and most likely dropping the tank and doing a custom pickup.I can see how returning the air bubbles back into the tank may cause problems if the tank is really low, but other than this what are the issues?

The reason I ask if its limited to other makes is because we have not found any problems with Cummins or Powerstrokes yet.............as far as fuel returns go.

Last edited by DSTRBD : 03-15-2005 at 07:06 PM. No, I have not dealt with nor talked to many Cummins guys
Last edited by DSTRBD : 03-15-2005 at 08:29 PM. You need to read what your typing. I know who you are so what, and in your words you arent sh!t to me, you have no idea of what your talking about and yet you tell people there is no problem but then reverse yourself with two different post and edited out what you said in others. I say if it walks like a donkey and talks like a donkey it's a donkey! If you were trying to gather information you would have not said "were not having problems with the Fords and Cummins." Then edit out what you said and come back with "I haven't talked to many Cummins guys!"
When was the last time you did any testing to figure out a problem? For that matter any design and testing of anything! I have no problem with distributors selling products but I do have a problem with people like you who jump in and have no idea about the subject and tell people there is no problem, when there is. We ran into the problem well over a year ago on Diesel Powers truck. I traced it down to one of two issues. Designed a new pickup to get rid of one of the problems only to find the other still there. Then built test fixtures and bought the hardware and did the testing and proved what was wrong. So I have seen the problem first hand and solved it, what have you done?

So is the problem the bubbly fuel being dropped down the filler neck or is the problem too much demand on the basket causing it to empty?

I do believe Fuel Preporator provided a solution by manufacturing ther AirDog 80. Since it only flows 80-90 GPH alot less fuel is being sucked out of the basket. Also alot less fuel is being returned down the filler neck. So basicaly they did provide a solution. I understand the Air dog does not provide enough GPH for the high HP applications but for the guy at 400 RWHP or less, it should do just fine.

The big dawgs can always use an Aeromotive pump and Aeromotive voltage box. Then you would have a true supply and demand system that was capable of flowing all the fuel you could ever ask for. Dieseltech I am sure you are on the verge of releasing your own set up similar to the Aeromotive solution.


On a side note, I am curious how much foaming occurs inside the basket? You would think the factory return line does cause some ariation, then it is sucked right back up by the pickup.

At least on my LLY, fueling problems don't become a big issue until 400rwhp. Yes, you can get 1093's at over 325rwhp, but the nuisance becomes dramatic as you go over 400.

Well the answer will be solved. someone will solve it. cant we get along.
we are here for the sport and the enjoyment. I am sorry some people have made good money on the site to now grow to dislike eachother.
Just like I am sure Eric is better at one thing or another than me. And visa versa.
we should all be in it to gain not tare down. $$$$$$ messes people up.
Steve is cool i met him in Indy. Could run circle around most of us. many of th venders and techs are dam good at what they do.
come on Diesel place was and is here for all. If a guy sell junk he will rat himself out.
enjoy thesport and quit crying.

cant we get along.
we are here for the sport and the enjoyment.

Patrick, we should all get along but sometimes you've been pushed just alittle too far and DSTRBD has reached that point with me. I've done alot here and on other sites to share some of the information we have developted. I'm not willing just to hand everything out but I am willing to get people thinking so that they can learn. I've given everyone enough information to figure out what's happening here with the fuel system design. God knows we've had plenty of discussions about it. I've called both Preporator and FASS and made them aware of the problems about a year or so back. So when DSTRBD jumps in and says there is no problem when he has no idea of what he is talking about it was the straw that broke the camels back so to speak. There are plenty of smart people out there who I'm sure will have firgured out the problem with the information that's been given without too much trouble.

Patrick, we should all get along but sometimes you've been pushed just alittle too far and DSTRBD has reached that point with me. I've done alot here and on other sites to share some of the information we have developted. I'm not willing just to hand everything out but I am willing to get people thinking so that they can learn. I've given everyone enough information to figure out what's happening here with the fuel system design. God knows we've had plenty of discussions about it. I've called both Preporator and FASS and made them aware of the problems about a year or so back. So when DSTRBD jumps in and says there is no problem when he has no idea of what he is talking about it was the straw that broke the camels back so to speak. There are plenty of smart people out there who I'm sure will have firgured out the problem with the information that's been given without too much trouble.:blahblah: :exactly:

:blahblah: :exactly:
Another "Troll" jumps in, with a whopping 5 posts.
Which one of your buddies "told" you to come over and post?

Somebody pass the popcorn, I want to watch DSTRBD and Diesel Tech finish this up without Trolls.

http://forums.corvetteforum.com/images/smilies/lurk5.gif (http://forums.corvetteforum.com/newreply.php?do=newreply&noquote=1&p=1550114624#)

http://www.bmdmax.com/images/gayassclown.gif

I have went back and read the posts and I see zero malacious intent anywhere...maybe some mis-information but I think there is a more tactful way of going about bringing that to the fore front. I have went back and edited posts when I was wrong about something....don't see a problem there. I have done business with DSTRBD and he has been very honest and very helpful. So to go and make assumptions about somebodies business intent is pretty rash. I just think we could do with out this jumping down peoples throat...its pointless. Really this entire thread should be done away with as soon as this BS started...causes this is where the info ends.

I have been scratching my head trying to make sense of this all. I have come to the conclusion that there has not been enough factual evidence presented in this thread by anybody for me to make any type of conclusion. I will have to do testing on my own if I really want to now whats going on with the fuel system.

I have realized that GM has done an oustanding job building a system that is reliable in all situations other than extreme HP situations. The basket explains why I can drive 1/2 mile up a very very steep rocky hill with 1/4 tank of fuel and my engine never misses a beat. I would hate to do any modification that takes that away from my truck. Regardles of who makes it and how it works. It could be deadly.

Dieseltech I hope you and all of your customers are very satisfied with your soon to be released fuel system.

McRat I hope you overcome the fuel starvation issues that prompted you to start this thread. Maybe some of the info presented here in this thread will get you closer to your solution.

I'm out.

We ran into the problem well over a year ago on Diesel Powers truck. I traced it down to one of two issues. Designed a new pickup to get rid of one of the problems only to find the other still there.
Sorry to come late into this. i was asked the question a page or two back if i did have this problem. And yes i did. My truck hasn't seen the fuel gauge move below the 1/2 tank mark for over a year.

My problem was the sender assembly is quite expensive. I want to say it was in the 400$ range for the whole assembly. I didn't have the money to buy a few of them and try drilling/cutting/modifying them to see which one worked best. Plus getting the sender out is a real PITA. i've dropped the tank in my driveway 3 times, and I must say it wasn't real fun.

So Steve bought a sender and modified it for my truck. It used the new pickup which Guy makes and I posted pictures of it quite a long time ago. Later I replaced it with a sender modified by Guy pictured earlier in this thread that has aeroquip fittings. This helped my supply problems, but made my starvation issue below 1/2 tank worse. I didn't opt to drill and put a seperate return in my tank so i switched to SD's returnless pump as an alternative. Its funny how you fix one thing and then it brings another problem to light. My truck has always been the fuel system bastard child as I used to have problems with fuel delivery that no one else had. Anybody who was at the LA dyno day over a year ago will remember when my bursting, farting truck blew the cardboard box to pieces.

I just got the SD's pump installed and running and haven't ran it down below a 1/2 tank yet. I'm carrying a 5 gal can of diesel in my bed just in case the problem is still there. I don't want to pull a Diesel5 and be stuck on the road:help: on the way to a dyno day):h . In all fairness at least i had a 45 gallon tank, so i had about 28 usable instead of David's 17..

With all of the new pump setups i'm sure one will work for you guys. it will just take some time to test. I'm on my 3rd fuel pump setup so far (holley, prep, now SD's). Good luck. We're all here to learn from eachother.

Someone had asked why this issue was never brought up about running down to half a tank. I for one will say this. I know why it happens, and have had many people ask me via pm/email if it happens to me. i've told everyone of them the truth- yes. I'm not one to go and say a product is junk as i put it on for 1 purpose- to increase my fuel pressure under load- and at the time it worked better than anything else i tried so i lived with the side effects. had I to do it all over again with my available options at the time i probably still would have. It allowed me to hold decent rail pressure which is all i really cared about. But now i decided i wanted to try and get below 7300lbs. so i removed the 45 gallon tank and put the stocker back in. This forced me to try and solve my 1/2 tank problem. Hence me giving SD's pump setup a try. Time will tell.

And guys PLEASE try and keep this thread on a positive note.

Thanks

Another "Troll" jumps in, with a whopping 5 posts.
Which one of your buddies "told" you to come over and post?

Somebody pass the popcorn, I want to watch DSTRBD and Diesel Tech finish this up without Trolls.

http://forums.corvetteforum.com/images/smilies/lurk5.gif (http://forums.corvetteforum.com/newreply.php?do=newreply&noquote=1&p=1550114624#)

Kinda like the guy in the lift pump thread.:rolleyes:

I think for someone to fully understand what's going on here they would need to have a first hand look at the sender. You simply can't pull a volume of fuel out of the sender cup that is greater than it's filling capacity. As mentioned here once you are below the level where fuel spills over the top lip of the cup you are now filling the cup via the check which is located at the cup bottom. This check has to replenish the level faster than the given pump is removing fuel or this level will begin to drop untill air enters the pump suction. The only solution would be to design the cup to fill quicker, or return less fuel. IMHO the simplest and most economical solution would be to use a better designed pump that can deliver desired volume based on your needs without the return fuel. If you already have a FASS or Preporator pump and are having problems you have two choices. You can ditch the pump or do the above mentioned mod to the system unless someone discovers a better solution. I've decided on the simpler approach.

My .02,
Tommy

I guess the ultimate question is.....will a pump that does not return fuel, be able to supply enough fuel to the system under maximum HP conditions as quickly as the engine demands it?

Remeber the rules "PTO"....................Pressure, Time and Orifice. :D

I agree that application and personal preferance will be the deciding factor. What will be the best solution for most of the diesel population may not be satisfactory for others who seek to bring out every HP available no matter how small. Shaving off small amounts of time in the decimal range may mean the difference of a win or loss. Liking a lot of power but not being one to attend competative events I opted for the J/K lift pump for its simplicity and effectiveness with long range durability. I just never realized a meaningful gain for my applications when running the larger pumps.

. Dieseltech I am sure you are on the verge of releasing your own set up similar to the Aeromotive solution.
We have two different systems testing but niether of them are ready for release. One will be for the high Hp guys and the smaller system for the people in the 350 Hp and less. The systems are nothing like the aeromotive units other than they pump fuel. Our systems are designed for diesel fuel and come with all the electronics and installation hardware to install them. All the customer will need is some hand tools and the time to install the system. Both system will feature full automatic bypass so you can disable the pump system and still have the fuel system work as it did from the factory.When the testing is completed and they do the job they will be released but not until then. The fuel pickup was released about a year back so if your looking for one of those we already have them.

=Trippin]Another "Troll" jumps in, with a whopping 5 posts.

Which one of your buddies "told" you to come over and post?



Somebody pass the popcorn, I want to watch DSTRBD and Diesel Tech finish this up without Trolls.



No disrespect to you guys and no trolling,just pointing out the fact that Steve does over hear what he tries to do elsewhere.Yes he is smart but his holier than thou attitude along with his inflated ego keep him from doing great things.

Good example is "Only he knows how something is done right and nobody else has a clue" .Problem is he himself has never had any fast diesel that he has owned.I build and sell fuel systems for the Power Stroke,before you say this is not a Power Stroke site let me say in Steve's own wordsInjection setups do matter. The result of how they matter is shown with CP testing. That does not change the fact that the same basic principles apply to all direct injected diesels. The bottom line is the injector injects the fuel into the cylinder on all direct injected diesels. Pretty simple, what is different is how the injector itself works. A common rail system makes the high pressure and feeds the injector, a IH injector makes the high pressure within the injector.The same applies to fuel systems you want good unaireated fuel to the high pressure pump.Looking at the fuel tank on your trucks the problem lies in the design and layout of the tank not that the Airdog or fass systems will not work.We had similar air problems on the Fords which have since been non existent with the replacement fuel systems we sell.

If you want entertainment just look here

http://forums.thedieselstop.com/ubbthreads/showflat.php?Cat=&Number=2290653&page=0&view=collapsed&sb=5&o=31&fpart=1

So how do we fix the problem then smart guy?

Edit: or how about telling us exactly what the problem is.......

David
Glad you came and joined us. I see your still putting your foot in your mouth here as well as there. The Ford fuel supply system is completely different than the GM. Just for some basic starters the Ford runs fuel pressure of ~60 psi to the injector, The GM runs at 23,000 psi to the injector. CP testing is the same on all the diesels as the quote you posted of mine says but that has nothing to do with the supply system, they are completely different! As far as the thread over there everyone should start in the beginning then read the whole thing. You might also want to tell everyone where you copied your Ford fuel system from, Bryan Kinney's truck. wonder who design it for him two years before you brought yours out! . I will make you the same offer as before. I will put one of the Duramax's we work on up against your race truck in a 1/4 drag race and give you a .5 second head start and we will see who wins. Now I know your race truck weight is ~5500 lbs and our truck weight is about 6500 so that's just alittle more advantage for you. If you don't like that Challenge how about showing up on the west coast with one of your Ford 7.3L puller trucks and we will run that with a 7.3L ford. That offer has been there for two years but you have yet to show up for that either. You might like to ask Mike L. about me having fast diesels and fast vehicles in general. I would venture a guess that I've owned more fast vehicles than you have owned vehicles.
As far as knowing more than everyone, not event close but, when it comes to you and your buddy Nate that's easy.

No disrespect to you guys and no trolling,just pointing out the fact that Steve does over hear what he tries to do elsewhere.Yes he is smart but his holier than thou attitude along with his inflated ego keep him from doing great things.

Good example is "Only he knows how something is done right and nobody else has a clue" .Problem is he himself has never had any fast diesel that he has owned.I build and sell fuel systems for the Power Stroke,before you say this is not a Power Stroke site let me say in Steve's own wordsThe same applies to fuel systems you want good unaireated fuel to the high pressure pump.Looking at the fuel tank on your trucks the problem lies in the design and layout of the tank not that the Airdog or fass systems will not work.We had similar air problems on the Fords which have since been non existent with the replacement fuel systems we sell.

If you want entertainment just look here

http://forums.thedieselstop.com/ubbthreads/showflat.php?Cat=&Number=2290653&page=0&view=collapsed&sb=5&o=31&fpart=1
Let me get this straight; The factory ( GM in this subject ) builds a fuel tank and system and an aftermarket company comes along and builds a fuel pump for it and this fuel pump does not work properly. Are you saying this is GMs fault? Are you saying GM puts the air in the fuel system? How about your statement on the Fords. I have never heard of a Ford having air in the fuel system from the factory. That air got there because someone put a inferior part on it and maybe your product fixed it maybe not. Nevertheless you did not fix a Ford problem because it didn't have one just like the Duramax. As far as Steve Cole never owning a fast diesel; you are grabbing at straws here and you are sounding more and more like a troll. You talk big yet you have no facts. What have you built or owned that is fast and stayed together and made it home?
mike

Ok great

I've got a new FASS pump and Trippin's fuel pickup and larger fitting's sitting on the work bench in the garage waiting for a warm day to install them but now I'm reading, don't bother because once you fall below 1/2 tank you will be sitting on the side of the road :mad: Censored

So do the larger ST aftermarket fuel tank's come with internal baffles, and if they do does it help?

Can the cup that seems to be emptying out and causing some of the fuel starvation isues be removed all together and then just extend the fuel pickup farther down closer to the bottom of the tank?

Seem's there are plenty of other cars and truck's that do not have this CUP style fuel pickup and they have no problem's going up or down a hill, why can't we?

Can the return line from the FASS be reloacted to the front or side of the tank down low near the bottom of the tank with a new bulkhead fitting so it does not compound the problem by aerating the fuel even more, which is what the FASS system is trying to do away with (air) in the first place?

Wish I had read somewhere on this site that people that had these system's already (FASS or Air Dog) were having problem's with fuel starvation when they were below 1/2 tank, I think I would of gone a different route with a lift pump.

Just happen to mail away my paperwork for an Extreme progam from Steve today, and now it seem's to me either I have the fuel rail starve for fuel with the high HP setting's and therefore not realize the max potential of the program, or install the FASS anyway and not drive around below 1/2 tank, which is very unpractical and sometimes unavoidable.

Live and learn right, it's only money :rolleyes:

DD

Mr. David Lott AKA Powerstroke Racer AKA Dimoja

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

How can you sleep at night?

<o:p></o:p>

The fuel system that you suggest that you invented is on my truck, designed by Steve Cole 2 years before you even knew what a diesel truck was.

You first attempt at this was what we would call a joke, using rubber lines for diesel fuel. Still running the fuel out of the stock location didn’t solve anything, Some how you managed to copy yet again a design that I came up with, with the help of Steve to run a fuel plug into the main ports of the heads. Since that time there has been big improvements done to the fuel system, and so far we have been able to keep a lid on it. Almost every product that you so called invented has been copied, stolen by you; I have yet to see an original product come from U.

Even your injectors we copied from industrial injection in SLC. How ever I do understand that you are very proud of your truck and the accomplishments that it has done and I will applaud you on that but to steal someone’s product and to say you invented it is wrong, You have had it in for me and Steve Cole for years, and I will tell you will never, never check up to Steve. Me you might, Steve has been my friend for a very long time and I would hate to be on his bad side as I’m seeing you are heading that way. I think once again you are putting your foot into you mouth, or you are just ignorant behind a keyboard,

You and your crew have basically monopolized the diesel stop with having you employee’s as monitors on that site, if you tell the truth about you or even give anyone the hint about it the thread is locked or deleted,

To date on DC I have only deleted 1 topic, and locked one thread.

David all’s I ever here from you about Steve or I, is how come we do not produce a dyno sheet, Well My truck is no dyno queen nor do I have to prove anything to U or anyone else, Sorry if this sound rude but that’s just the way it is, We (Steve) and I use the dyno to tune and test our products not to get high, exaggerated horse power numbers, On your web site you guarantee 450HP with your set up but do you guarantee that the motor will not throw a rod or a head gasket? Both Steve and I know what my truck will do and how it runs, and there still is room to grow, To date the only thing we have done was have a head gasket issue which for the record was my fault not Hypermax’s

Granted your truck is a drag racer and my is a sled puller so I’m sure we will never run side by side on a drag strip or a sled pull. So I will explain it to you this way.

David I’m sure you would love for me to line up with you on a race track but the chances of that happening are like the chances of you ( powerstroke racer) and ( Dimoja) being at the same place at the same time and being to different people. And if I do show up anywhere you are, you can beat I will be using my truck, I will not leave it on the trailer and brag about how fast it is.

Just some helpful advise to U

Having Steve on you good side is a very good thing

Having Steve on your bad side is like having a nightmare that just will not go away.

Having me on your good side is a safe thing

Having me on your bad side is like having an even worse nightmare.

<o:p></o:p>

What a joke.

Back to the subject at hand here. Fuel tank was pulled. Looks like some serious flaws on GM's part. We have an idea that we think will work. Testing will not start until tomorrow though. Pics to follow.

I guess I will ask the question others have asked:

IF the basic problem of fuel foaming due to large amounts of fuel returned to the filler neck with either FASS of AirDog...would returning the fuel to the inlet to the pump via a T in the line or a T in the stock fuel return line help the foaming and thereby help the problem of sucking in air while operating at lower tank levels.

I have the Airdog and have run down to 1/4 tank and have not had issues. I also Run B20 most of the time and notice it foams a lot less than straight D2...so I could be masking the problem.

I did have an Airdog set at 12psi that caused problems and would set an overpressure code...but the new one at 10psi is now running without problems.

Monday I will call the Airdog guys and ask them about this problem and see what they say.

Looks like some serious flaws on GM's part.
Once you understand how they designed the system you will figure it out and there are no flaws in the sender assemble. It does just what it is suppose to do for the power rating of a stock engine. I've run 480 RwHp out of the so called flawed LLY sender without a problem with the proper fuel system setup at less than 1/8 tank! We have also run 534 RwHp out of the LB7 sender which is almost the same thing at 1/8 tank. The major difference between the two senders was the addition of a fuel vent to help with fillups with the bigger LLY fuel neck. The only thing modified in both senders was our pickup.

I think the airdog should be left out of this conversation. It is not the same unit that has given these guys problems. They are refering to the FASS and Preporator 135A. Those units are big and obviously flow more fuel then required by the engine or they would not be dumping any extra fuel down the filler neck.

The air dog 80 flows about 50 GPH less than those units. So the demand on the basket and the amount of fuel being sent down the filler neck is greatly reduced when compared to the bigger units that have caused problems.

So these problems really only apply to the west coast guys running the FASS or the Preporator 135A.

I found the Airdog to be much worse than the FASS. I am probably one of the first people to install the Airdog in the Duramax as I was sent every bracket , fitting , and wire harness for install on DIESEL 5s Duramax. I was asked to take pictures and give a report as to what fit and how. I gave no such report back because DIESEL 5 was charged full price on the kit and told it was the cats meow for the Duramax. After I recieved the kit and called the company, I was told they had never installed one on the Duramax. Both the FASS and the Airdog will work ok to a point, but not with the big pick up. They have flaws and the big pick up amplifys them. DIESEL 5s Airdog failed electronicaly and stranded him as the the fuel would not deliver through the failed pump and the truck would stall if fuel level dropped below half tank. FASS was better but cranking engine to get it started below half tank put a burden on the starter motor. All of my testing was done with the big pick up, none without it. This is what I base my test results on. Other trucks may run differently with the same setup.

Well if the problem seems to be the CAN that surrounds the pickup (im reasoning that it looks like a can and works like a small reservoir from people's post's since I haven't seen one in person yet) then why not cut down the can height so fuel will still spill over the top when the fuel tank is below 1/2 tank, or better yet make a new can that is somewhat shorter but MUCH wider so it will hold a good amount of fuel that the pumps can't empty out fast enuf as they can be refilled.

And since Trippin's designed larger pickup and fuel fitting's with a larger line internaly why not also increase the return lines internally so that lift pump's can T into them also and return the fuel to where the factory system does.

Just thinking out loud

Ok great

I've got a new FASS pump and Trippin's fuel pickup and larger fitting's sitting on the work bench in the garage waiting for a warm day to install them but now I'm reading, don't bother because once you fall below 1/2 tank you will be sitting on the side of the road :mad: Censored


Live and learn right, it's only money :rolleyes:

DDDD,

Remember, the "Billet Pickup" only makes it easier to draw fuel from the tank. It will improve a non-lift pump fuel system as well as a fuel system with a lift pump. If you have a pump that bypasses alot of fuel under cruise/idle conditions, it is conceivable to dry up the canister that the pickup is housed in, at or below 1/2 a tank of fuel.

An easy fix. Don't race with 1/2 a tank or less. Turn off the Fass when you get near 1/2 tank.

Or return the Fass and wait for the "Xtreme" pump system that Diesel Tech is working on.

You will need an enhanced fuel system for "Xtreme" WOT runs.

DD,
I want you to be 100% satisfied with any product purchased from me. If you are only 99.9% happy, feel free to return the "Billet Pickup" for a refund. :D

Back to the Powerstroke Racer/DSTRBD vs DieselTech/Mike L. tag team match.
:lol:

On Edit:
I manufacture and market the "Billet Pickup" and many have taken to calling it the "Trippin Pickup".
However, credit where credit is due.
It is based on an original design by Diesel Tech.

Hey Mike L that is some great info about the airdog. I assumed you were using either the Fass or larger Prep 135 A and not the correctly sized airdog.

In an earlier post you mentioned that there were lots of bubbles coming out of the line and into your bucket. There are two lines coming out of the air dog. Which line was creating all of these bubbles? The return line to the filler neck will be full of bubbles by design. The clean side will be virtually free of all bubbles by design.

I also noticed you said the truck would not work when the pump quit working electricaly, it does have a bypass. The bypass is so good that there is virtually no vacum created by the airdog when installed yet turned off electrically.

I wonder if somehow you had the clean feed line going to the filler neck and the dirty return line going to the engine. The ports are right next to each other.
The return line is on the left and the clean line is on the right if you have the ports facing you.

Well if the problem seems to be the CAN that surrounds the pickup (im reasoning that it looks like a can and works like a small reservoir from people's post's since I haven't seen one in person yet) then why not cut down the can height so fuel will still spill over the top when the fuel tank is below 1/2 tank, or better yet make a new can that is somewhat shorter but MUCH wider so it will hold a good amount of fuel that the pumps can't empty out fast enuf as they can be refilled.

And since Trippin's designed larger pickup and fuel fitting's with a larger line internaly why not also increase the return lines internally so that lift pump's can T into them also and return the fuel to where the factory system does.

Just thinking out loud

Do not T into the stock return lines with high bypass flow/pressure unless you want a real problem on your hands. Bulkhead fittings on the tank works really well and I bypass a large amount of fuel. I do get some foam at a 1/4 of a tank but I have never stalled on the road, even at low fuel levels. I do race on a full tank(s) though. :cool:

Hopefully when all the territorial pissing is done in this thread some useful information will come of it. I guess the east coast and midwest guys will just keep getting it done while the big chickens keep squabbling.... :rolleyes:

Do not T into the stock return lines with high bypass flow/pressure unless you want a real problem on your hands. Bulkhead fittings on the tank works really well and I bypass a large amount of fuel. I do get some foam at a 1/4 of a tank but I have never stalled on the road, even at low fuel levels. I do race on a full tank(s) though. :cool:

Hopefully when all the territorial pissing is done in this thread some useful information will come of it. I guess the east coast and midwest guys will just keep getting it done while the big chickens keep squabbling.... :rolleyes:
East Coast and Midwest keep getting it done?

:lol:

East Coast and Midwest keep getting it done?

:lol:
Easy Big "GUY"............you know us Eastcoasters :grd:

Especially PEACHES..............;)

I remember about 3 or so years ago before this site started when the Central and Easteners were running lift pumps and the Westeners were at war with us stating that a lift pump was not needed, overkill, justifing air lock of a certain filter, Blah, Blah Blah. An explanation of the many benefits then fell on deaf ears. Now all of a sudden the idea originates in the West. Go figure! And yes I have nothing better to do on a bright sunny Saturday. :lol: :stirthepo

Gale Banks invented the turbo and the diesel, so it only figures that the rest of the coast invented the fuel system for it.

I remember about 3 or so years ago before this site started when the Central and Easteners were running lift pumps and the Westeners were at war with us stating that a lift pump was not needed, overkill, justifing air lock of a certain filter, Blah, Blah Blah. An explanation of the many benefits then fell on deaf ears. Now all of a sudden the idea originates in the West. Go .
That's probably still true for anything under 150 hp ? :D Was there anything available over hot juice 3 years ago? :stirthepo

<HR style="COLOR: #d1d1e1" SIZE=1><!-- / icon and title --><!-- message -->I found the Airdog to be much worse than the FASS. I am probably one of the first people to install the Airdog in the Duramax as I was sent every bracket , fitting , and wire harness for install on DIESEL 5s Duramax. I was asked to take pictures and give a report as to what fit and how. I gave no such report back because DIESEL 5 was charged full price on the kit and told it was the cats meow for the Duramax. After I recieved the kit and called the company, I was told they had never installed one on the Duramax. Both the FASS and the Airdog will work ok to a point, but not with the big pick up. They have flaws and the big pick up amplifys them. DIESEL 5s Airdog failed electronicaly and stranded him as the the fuel would not deliver through the failed pump and the truck would stall if fuel level dropped below half tank. FASS was better but cranking engine to get it started below half tank put a burden on the starter motor. All of my testing was done with the big pick up, none without it. This is what I base my test results on. Other trucks may run differently with the same setup.

Good info on the Airdog Mike. The problem lies in the stock pickup/return and where the Airdog returns the airated fuel to. It essentially dumps it right back on top of the pickup which is towards the front of the tank. So when accellerating hard or when the tank gets low, bad things. This can easily be solved by ditching the stock pickup for one the sits near the rear of the tank. We are going with a sump for the feed and leaving the stock return the way that it is. Will it work? We will soon find out.

abear

Were you not the one saying lift pumps were only to keep the air from forming in the Mega filter, and Mr. Kennedy said lift pumps did no good in the Hp department? I seem to remember a few long threads with Diesel Tech, you and Kennedy, where Diesel Tech posted both before and after graphs showing where the lift pump added to the high power trucks.

DSTRBD,

With the feed in the rear what happens under braking?

I'll have to agree. The lift pump is needed more now than ever. It's how much pump and how much one is willing to put up with that I often disagree with in terms of Cost/Performance benefit. What it comes down to is how much someone wants to spend and will the returns measured in HP be satisfactory to that person for the investment and time. Each individual will have to decide for themselves what they are trying to accomplish. Some people will stop at nothing to squeeze out that couple of extra ponies. We are all different. For those that are bringing the DMax to its limits I say :cool2: .

Trippin- Its not all the way in the rear, just towards the rear in a place where braking shouldnt matter unless the tank is very low. On the flip side of that, what happens to the stock pickup with a low tank under hard accelleration?

We think it will be much easier to ditch the stock pickup. There are too many things working against it for high HP applications especially when running an airdog or fass with less than 1/2 a tank.

abear

Were you not the one saying lift pumps were only to keep the air from forming in the Mega filter, and Mr. Kennedy said lift pumps did no good in the Hp department? I seem to remember a few long threads with Diesel Tech, you and Kennedy, where Diesel Tech posted both before and after graphs showing where the lift pump added to the high power trucks.

DSTRBD,

With the feed in the rear what happens under braking? Please show me a related post which prompted this reply. Surely you're not sensitive to a little East/West messing about. I would like to think you're a little more mature than that. But just to answer your question, Nope, I Didn't say that and feel free to quote any of my old posts. Make sure to place a little helping of crow in front of you when you search because you may get hungry a few times while looking. I generally live by the ole rule that the truth is always easy to remember which explains my ability to recall things I said in the past. If you find where I said something different shame on me but if you find nothing shame on you so have at it. I did say that HP gains were null to mininal and the charts reflected just that. I did say that the setup design was more important than a installing a mega pump and that has now proven to be true, correct. I still believe that a proper setup is more important. I think a couple of guys are now working on that. However, As I said I do agree there was some (a little) HP increase so lets be clear on that. Not much but it was there. Maybe you are seeing more gains now. Dunno and could care less but I expect it isn't that much more. I did post the many benefits of the lift pump when I first installed one back when we were all at the DieselPage and my truck was new. Primarily but not exclusively for stopping normally occuring air in the system that exhist with ANY filter but was only stopped by the Mega filter. I maintain my position that ALL systems under vac has vapors pulled out of solution. No exception! Anyone that remembers those old posts will attest to that. Not sure how this came out of a simple East Coast West Coast fun picking. Do you really beleive the coast makes the person? I hope not. If it makes you feel any better the lift pump idea started in the West. Now I said it. Hell were generous down here. We even shared a National title with SoCal in 2004 after only minimal crying. Unlike SoCal was willing to do with unbeaten, harder scheduled Auburn. :confused:

Not to answer DSTRBD's question but it's called inertia. Something that is not seen on a dino as the truck is not moving and G Force is not a player in pressure fluctuations. That is if pressure change under acceleration and breaking is what you are refering to. Remember, a dino and moving mass is a little different. A dino measures only static HP with associated pressures under those conditions.

You can not change the basket. It is there for a reason. It collects fuel when sloshed, this allows the basket to stay full under any circumstances insuring fuel delivery no matter what. I have driven down and driven up steeper hills then most , the basket works.

There is a 265.00 dollar voltage stepper from Aeromotive that would fix the problem of too much return fuel.

The other fix would be to return fuel at a different location as previously stated by BMDmax.

Fianlly a simple restiction placed in the return line, although too much fuel might be fed to the engine.

I still do not believe the smaller airdog causes as signifigant as problem as the larger Fass or the larger 135 A.

In general how high the pressue is set will determine how much fuel goes to the engine and how much fuel goes to the filler neck. There could have been problems with the regulator or the insallation.

In about 1 week I will test a correctly installed/operational airdog at low fuel levels. If there is a problem I will provide a simple cost effective solution for exisiting customers and also potential new customers who still like the idea of an all in one fuelpump/filter system.

I have already verified the bypass funtion and also Trippin mentioned using his truck with the FASS shut off so we know they bypass. Why one unit would not bypass???????

Bronco,

I should mentioned that I had two Airdogs...one set at 12psi and one set at 10psi.

There were no problems as far as running the tank down...lowest I ran was about 5 gallons left on both pumps.

I seem to remember that Problemchild posted an aftermarket special fuel tank pickup.....from HOLLEY........

http://www.dieselplace.com/forum/showthread.php?t=18348

I have my own fix for this problem.........if it works I may decide to share it.........:D

I have an extra 26 gallon tank STOCK tank to play with............when time allows I will do some modifications on it and see what if any difference it makes.......:eek:

It has been no secret to racers that all 1/4 mile cars use a low rear sump with a pickup at the bottom of the tank........http://www.dieselplace.com/forum/images/smilies/cool.gif .........The only need for a rear sump or a pickup at the rear of the tank is for constant fuel delivery under hard accelleration.........as inertia causes the fuel in the tank to sit there under accelleration, ensuring a resevoir of fuel even in a low fuel level tank condition.

It is also no secret that inertia overcomes the stock vacuum fuel system and causes a mid track stumble on a big tune without a lift pump.........at least it did in my experience before adding a lift pump.

The wrong lift pump will cause air, foam or an empty basket..........all bad........:rolleyes:

So then..........I hope to have my test tank ready by mid April..........I need to wire my Fuel pressure gauge and get with Mackin for some TECH II snap shots...........

I will share my findings if they prove out..........time will tell.

Thttp://www.dieselplace.com/forum/images/smilies/wink.gif NY

abear,

I wasn't quite myself this morning so forgive me if I errored. :hug:

I was just going from memory on the great lift pump debate. :shootself

In fact because I'm "immature", I'm always up for a little East/Mid/West funning around. :D :Pshyco:

You said null to minimal gain. Isn't null/nada/zilch/zippo the same as zero?

Just so I'm clear, what is your definition of minimal? :help2:

Minimal gain to me would be less than 10hp on our Durmaxes. :eek:

What I find funny is the pickup and reservoir can are one in the same between the LLY and LB7. So the problem will occur with either application. If you toss the high return type pump out the window the problem goes away. If the Fass/Preporator work as advertised what happens to the air it removes and pumps back into the tank with the fuel. Would it not make sense that it ends up in the fuel again? Since the air is pushed back into the tank what happens when your not returning any fuel to the tank? Simple, it goes to the engine! The lift pump was neither a east coast or west coast idea......... it was and still is a German idea. Bosch calls for the lift pump in the design specifications for a common rail system. GM found they could do without it at the Hp level they run the engine at. Look at a Cummins with the common rail it has a lift pump and uses the same CP3 high pressure assemble as the Duramax does.

Tommy we had many heated discussions about the lift pump and I can remember both you and John telling me it did no good for Hp, as a matter of fact event after I posted the before and after graphs you and John questioned it! If you call trying to get the last little Hp out of the truck something you do not want then there is no need to have a lift pump as the stock GM system works fine at stock Hp levels. Look at the Nicktane filter kit, it filters every bit as good as the Mega filter but it has no stalling issues, look at the guys that have moved the filter from under the air filter housing that had the same issues as the Mega filter to the second alternator position, problem solved............. ever wonder why? It's truly very simple.... gravity! With the filter located under the air filter housing the CP3 pump drains down hill to the filter when the truck sits for long periods. The air comes in via the return line on the system. Look at the stock system, the CP3 pump assemble is lower than the stock filter so it does not lose its prime. This is the same reason that moving the filter to the second alternator position solves the problem. With a vacuum type system the filter never get completely full of fuel, you can see this when you cut one open and look at the filter, its dirty at the bottom and as it plugs it works its way up the filter. The lift pump is just a coverup for the problem induced by placing a filter lower than the CP3 pump and allowing it to drain back and lose its prime. You can solve that problem with a simple one way check valve!

You and I have had a few PM's and after I explained how and why I was designing our system I think we now agree about how to do the lift pump system. So lets now take a look at the base problem occurring as it so simple its not funny. You cannot suck the fuel from the can faster than it can be filled, that's it! The Fass/Preporator will do it at anything less than about 1/2 tank. So you need to either fill the can faster or slow the wasted fuel down so you don't empty the can. Until you solve this problem you can move the pickup anywhere you want in the tank it isn't going to work!

As for the stock fuel being returned into the can improperly someone had better look a little harder at what is truly there. The method GM used is very sound and works great at 500 + Hp on LB7 vehicles so it has nothing to do with the LLY setting P1093 codes!

as a matter of fact event after I posted the before and after graphs you and John questioned it! Which before and after graphs.....I remember a discussion on Nick's truck....but I'd have to resort to the dyno excuse book....not the same day, dyno....or even program for that matter.

I remember when this went on, if indeed it is the occurance you are refering to, and Mac, Sdaver, Nick and I were communicating frequently and I am sure he got a new/different tune to run.

......not on a TTS rant or saying a lift pump is bad or not needed for that matter.

Trippin's perhaps?

Which before and after graphs.....I remember a discussion on Nick's truck....but I'd have to resort to the dyno excuse book....not the same day, dyno....or even program for that matter.

I remember when this went on, if indeed it is the occurance you are refering to, and Mac, Sdaver, Nick and I were communicating frequently and I am sure he got a new/different tune to run.

......not on a TTS rant or saying a lift pump is bad or not needed for that matter.
Nicks truck was never used for the testing, so your Censored wrong again. All you need to do is go back to the monster fuel pump discussion and you will find it clearly posted. It's seems as though you might have selective memory.

It was a members truck so I will leave it up to them if they want to step in and tell you. The graphs showed the same truck on the same Superflow dyno with no changes other than a lift pump. Also, going from memory I believe we had gains close to 20 RwHp, but some must not be looking for that small amount of gain. ;)

Nicks truck was never used for the testing, so your Censored wrong again. All you need to do is go back to the monster fuel pump discussion and you will find it clearly posted. It's seems as though you might have selective memory.


Tensions must be high in the west.....don't they have hookers out there?):h

Relax peter..I just want to see what the "verdict" is without having to read through 10 pages of you telling someone they are wrong:rolleyes: ....it gets old...even to someone like me;) ......try and have a nice day.

Then why noy ask a simple question before you make a statement that is false and misleading. Why bring up all the crap about different day, different dyno, different program when you had no knowledge if not to just :stirthepo Must be an east coast thing!

I think the airdog should be left out of this conversation. It is not the same unit that has given these guys problems. They are refering to the FASS and Preporator 135A. Those units are big and obviously flow more fuel then required by the engine or they would not be dumping any extra fuel down the filler neck.

The air dog 80 flows about 50 GPH less than those units. So the demand on the basket and the amount of fuel being sent down the filler neck is greatly reduced when compared to the bigger units that have caused problems.

So these problems really only apply to the west coast guys running the FASS or the Preporator 135A.Bronco,

The last L/P I tried was the AIRDOG FP-80 (Serial # 20248) the pump had the same issues as the above and died after couple of months. If you do decide to go with the AIRDOG....I got a case of filters at half price for ya.http://www.dieselplace.com/forum/images/smilies/wink.gif

Well so far no 1093 and no air bubbles in the return line back to the tank.Pictures and more details to follow.


Guys this LLY rocks,mind you I'm a Ford boy.Might have to see how fast a Ford diehard can make a Dmax run:)

If the Fass/Preporator work as advertised what happens to the air it removes and pumps back into the tank with the fuel. Would it not make sense that it ends up in the fuel again? Since the air is pushed back into the tank what happens when your not returning any fuel to the tank? Simple, it goes to the engine! Separation by floatation is where some of the air goes.

Some of the air does just what you said, it gets sloshed into the fuel and go's right back through the unit. The unit takes it right back out again and sends it right back down the filler neck.

It is not really important what happens to the air, it is more importnat that the feed to the engine is free of dirt, water and air.

Secondly the Preporator has a small passage/port that allows a small amount of fuel/air to be returned to the filler neck even when the regulator check ball seats. Upon close inspection you will see this port makes the Preporator different then the competitors.

The sizing of the pumps is crucial. There has to be enough flow to maint pressure to the engine and also return to the tank otherwise you are correct, they do not separate air very well when there is no flow to the return line.

Bronco,

The last L/P I tried was the AIRDOG FP-80 (Serial # 20248) the pump had the same issues as the above and died after couple of months. If you do decide to go with the AIRDOG....I got a case of filters at half price for ya.http://www.dieselplace.com/forum/images/smilies/wink.gif
Actaully I recently exchanged my unused Preporator 135 A in for the new Airdog 80. I never installed the 135 because I knew it was just to big. Physically and flow.

I have had the 80 since last Wensday. That is why I have chosen to get so involved witht this thread. I have concerns about the upcoming installation, with the recent info that you, MikeL and Steve have presented.

I am trying to sort through the junk and learn what I can to insure asmooth installation and a product that works like it should for a long time to come.

I am really hoping that your experince is isolated.

I am honest, and if I have problems I will post here. It should be installed by next weekend. If all goes well, I will be calling you about the filters.

Trippin, Likewise I didn't mean to get twisted off like I did. I felt as though I was called out at the time so I did quickly get on the defence. After I saw Steves chart back then there was no way I could have denied that more HP was acheived so I couldn't have conceivably said there was no gain. Right! It was right there in front of me and the public. I vaguely remember it wasn't that much but as I said a couple posts back in this thread I do respect the fact that every bit of acheavable HP is important to you guys in the competion area. This is cool and gives the rest of us owners not in the competition world something to look up to as far as DMax performance. For the record If I did happen to say at some point before I saw the charts that there would be absolutely no gain, all I can say now is that I goofed.

Trippin, Likewise I didn't mean to get twisted off like I did. I felt as though I was called out at the time so I did quickly get on the defence. After I saw Steves chart back then there was no way I could have denied that more HP was acheived so I couldn't have conceivably said there was no gain. Right! It was right there in front of me and the public. I vaguely remember it wasn't that much but as I said a couple posts back in this thread I do respect the fact that every bit of acheavable HP is important to you guys in the competion area. This is cool and gives the rest of us owners not in the competition world something to look up to as far as DMax performance. For the record If I did happen to say at some point before I saw the charts that there would be absolutely no gain, all I can say now is that I goofed.
*:beerchug: *

Well so far no 1093 and no air bubbles in the return line back to the tank.Pictures and more details to follow.


Guys this LLY rocks,mind you I'm a Ford boy.Might have to see how fast a Ford diehard can make a Dmax run:)

No P1093's at XXX HP level? Please name the tuner(s) used. Other mods?

P1093's might not be entirely fuel system related. A 440HP tune doesn't throw P1093's often, while a 375HP tune will throw them daily. It certainly DOES have something to do with fuel supply as a dirty filter will aggravate the condition.

Many tuners will only throw the code once per 1000 miles or less. Other will throw it daily. To say a setup doesn't throw them, means you should do at least 2000 miles of varied driving (towing, racing, etc) to be sure.

No P1093's at XXX HP level? Please name the tuner(s) used. Other mods?

P1093's might not be entirely fuel system related. A 440HP tune doesn't throw P1093's often, while a 375HP tune will throw them daily. It certainly DOES have something to do with fuel supply as a dirty filter will aggravate the condition.

Many tuners will only throw the code once per 1000 miles or less. Other will throw it daily. To say a setup doesn't throw them, means you should do at least 2000 miles of varied driving (towing, racing, etc) to be sure.:exactly:

Which tunes make 440 and don't throw P1093 and is that with or w/o a lift pump?

I would realy like to know as my truck throws P1093 easily. I can duplicate it almost everytime within 30 miles of driving, and that is waiting 10 miles to let things warm up.

Trippin,
I'm happy with the fuel pickup you sent me and realize that at higher HP you need an increased fuel flow to supply the engine with. What I didn't realize when I bought my FASS pump was that the pump would actually be TOO fast for the truck, I figured if a small pump was good a larger pump would be better, but I'm now reading that could be a mistake. I never knew about the unbaffled tank's and this CUP or BASKET that the fuel pickup sit's in. I didn't know that the larger pump's could empty out the CUP faster than it could be refilled by the one-way check valve's in the CUP and possiblly suck some air into the fuel inlet. Did you mention that the FASS could be turned off electrically and still be a flow-thru, supplying enuf fuel to keep the truck running down the road, even with the filter and water/fuel seperator model, which is the one I have.

But the BIG question is if this CUP has any restriction's on the max HP of the engine, in other word's will these one-way check valve's let enuf fuel into the CUP to support 450 hp, 500hp, 550hp, 600hp, what's the limit? And if they will let enuf fuel in to supply the current HP war's, then what is the max draw out of the CUP that you can have without emptying it out, is it 50gph, 60gph, 100gph, and I guess that will be the determining factor in Lift Pump output.
You can't empty it out faster than it can be resupplyed.

For those that have seen the sending unit assemblly and had it apart, I ask you is there any way to cut down the top of the CUP so that more fuel can fall over from the top before problem's arise with a larger lift pump. Can you cut the CUP in half, is it made out of plastic like the pickup and use a DREMEL on it, so that you can go down to 1/4 tank before the CUP start's having to pull fuel through the one-way check valve's?

Or if that's not possible can a NEW CUP be built that is the same height but wider so that it will hold more fuel that can't be emptied as quickly?

Or can these one-way check valve's be modified so that they will flow more fuel into the CUP to fill it up quicker to avoid fuel starvation?


I like the idea of having my FASS pump not only for the lift pump to supply the engine with all the fuel it will ever need for any practical HP rating that I may use, but also for the extra fuel filter and fuel/water seperator that it has, and that the fuel supplied to the engine should NOT have any air in it, and the fact that most of the fuel get's recirculated a few time's thru the filter before it get's to the engine, which will help with injector's which are alway's on the back of my mind.

So I guess I want to eat my cake and have it too.

Any one have any idea's?

Ted are you out there, can I return my FASS?


Diesel Dragon
(pumpless and not liking it)

a new cup could be built, but that's beyond my means. you can drill holes in it, etc.. just know that if you do you risk starving for fuel when going up/down a hill at a low fuel level..

How big of a hill are we talking?
And how low of a fuel level?

now this is how we learn, rack our heads and answers will come. Just dont tare people down....

I looked at building a new cup, but it's internal shapes etc. are fairly involved. IMHO, we could drill some holes in the side and definitely lower the useable fuel level. This would be a trial and error situation.

On Edit: I drove every day for an entire month with my Fass turned electrically off. And it functioned just fine as a flow through design.

I like to test stuff. :D

I have no idea how the setup works so I am just stabbing in the dark here. Please go easy on me if I am out to lunch.

Could we put 2 cups side by side and T them together outside the tank?

4) 1.5" holes in bottom at 3, 6, 9, & 12 o'clock. 4) 2" x 2" square pieces of solvent tank drain rubber flapper thing (or diesel proof whatever so it doesn't role up) pop riveted over inside of hole (two rivets at 10:30 and 1:30 in the corners). All the fuel in you want. Acceleration or hard breaking lets more in the cup but none escapes past the "valves"...T

The things that need to be looked at are what will happen under different conditions. Once you do that you will find that GM did a very good job in the design. Once we improved the pickup we looked for a way to improve upon the reservoir design that would work in the stock tank. Bottom line was I found no way to improve upon the stock one without making many modifications to the stock tank. I felt this was outside of what most people were willing to do. We are currently testing a modification (been running it for a few months) that helps the fuel supply into the reservoir that does not lose the properties GM designed in from the factory. Time we let us know if it really does any good or not. When your looking at any modification to the design make sure and remember there are two tanks sizes and you must account for both since they both use the same assemble. That's 2 for the LB7 and 2 for the LLY. If you really want to play make a tank from clear plastic that's the same shape and size as the original, mount the sender in the same position as it is in the stock tank. Using water and a fuel container add water one gallon at a time and play with tilting the tank and see what happens. Go find the angle of some of your driveways and some local hills, then tilt the tank to those angles and see what happens.

Sorry if I missed this but why did this P1093 become more of an issue with the LLY? I am assuming the design is still basically the same? (I think I read that in this post) Are the parameters narrower for the fuel demand/actual pressure on the LLY?

Obviously the system worked fairly well on the LB7's why doesn't it work on the LLY's?

4) 1.5" holes in bottom at 3, 6, 9, & 12 o'clock. 4) 2" x 2" square pieces of solvent tank drain rubber flapper thing (or diesel proof whatever so it doesn't role up) pop riveted over inside of hole (two rivets at 10:30 and 1:30 in the corners). All the fuel in you want. Acceleration or hard breaking lets more in the cup but none escapes past the "valves"...T
Spend 400.00 like I did and look at the system, then you will see the errors in your idea.

Sorry if I missed this but why did this P1093 become more of an issue with the LLY? I am assuming the design is still basically the same? (I think I read that in this post) Are the parameters narrower for the fuel demand/actual pressure on the LLY?

Obviously the system worked fairly well on the LB7's why doesn't it work on the LLY's?
I was wondering if someone would get around to this.....................
You are correct the system designs are the same, so do you think someone might be looking in the wrong place?

So if it is S/W why hasn't a tuner changed the parameters to get around it? Not that simple?

Or is the rest of the fuel system limiting it? I've heard the rest of the fuel system on the LLY's was not as beefy as the LLY but I don't know either system well enough to confirm. I have a feeling Diesel Tech could fill us in. ;)

4) 1.5" holes in bottom at 3, 6, 9, & 12 o'clock. 4) 2" x 2" square pieces of solvent tank drain rubber flapper thing (or diesel proof whatever so it doesn't role up) pop riveted over inside of hole (two rivets at 10:30 and 1:30 in the corners). All the fuel in you want. Acceleration or hard breaking lets more in the cup but none escapes past the "valves"...T
Ynot,
That's an excellent idea, as Mike L. was saying the shape of the bottom of this "can" prevents us from implementing your idea. ;)
Once again I'm a firm believer in what GM was trying to do with the design and am trying to work through a way to enhance their design rather than eliminate it. Eliminating it is the easy way to solve the issue at hand but I'm afraid it will create other problems.

so, what's the BAR supposed to be set for on stock systems? I hear of a bunch of fellas running 5,6,7,8,9,10 Psi and some folks running almost 16spi.......where should an OEM system be set, with up to a 500HP box? ....... :drinking: :think:

We tested my LLY late yesterday and today with excellent results. As I stated earlier, we installed a sump in the rear 2/3's of the tank and also ran the Airdog. We then filled the tank half way and began testing with the Juice/Attitude an level 5. Truck ran flawlessly and the mysterious "dead spot" in OD dissappeared. Also, we could not get P1093 no matter what we tried. I used to be able to throw it on call when I would get into it more than 3/4 throttle. We then ran the PPE Hot Xcelerator and the results were the same. The tank is now on E. Still, zero problems.

We tested my LLY late yesterday and today with excellent results. As I stated earlier, we installed a sump in the rear 2/3's of the tank and also ran the Airdog. We then filled the tank half way and began testing with the Juice/Attitude an level 5. Truck ran flawlessly and the mysterious "dead spot" in OD dissappeared. Also, we could not get P1093 no matter what we tried. I used to be able to throw it on call when I would get into it more than 3/4 throttle. We then ran the PPE Hot Xcelerator and the results were the same. The tank is now on E. Still, zero problems.:ro) Thats great, but how low is the sump? I have a Super tank on the truck and it's already lower than the frame by 1" or so, lower in my case might not be a good thing.:( I also can set a the P1093 most any time when under 1/2 tank and getting on it, juice set on LVL1 or at 1/4 tank w/o juice, this was with the stock tank, I have not had a chance to try with the super tank- not empty yet):h .
Watching with intrest- need to solve this the stealer is no help:mad:
Marty

Trippin- What kind of problems do you think would happen if you eleminate the basket for fuel pickup?

Am I correct to assume the long bed trucks have a worse problem than shortbed trucks? The placement of the sending unit is just a bit forward of the tank center on a shortbed and about 2/3's toward the front on a long bed. That is just opposite of how it should be. When hard accelleration occurs all the fuel will go to the back of the tank uncovering the basket and either running out of fuel if the damand is large enough or pick up air,not ideal conditions. Then to make matters worse the fill tube is extended in the tank so that it falls almost on top of the basket. Looking at the frame and bed layout it seems that was the only place they could put it. I now fully understand what Steve was saying about the fuel return in the fill tube. Problem is he did not really say it.

My solution to this problem was to install a sump just before the back strap to the left of the tank center. We also installed the fuel return from the Airdog backwards so the returning fuel would be visible with the fuel filler cap removed. This would also allow the majority air to seperate from the fuel before re-entering the fuel tank. What we found was little to no visible bubbles once the pump was running for a few minutes.
We allowed the fuel level to go as low as the red mark on the gauge to see if if we picked up air during hard accelleration and hard braking neither of which happened. To test this we watched for the yellow light to come on which it finally started doing so the longer we ran on empty. We also turned the pump off to see what kind of differences were noticed. The first thing was the sound of the engine with pump on or off. The engine seemed to run smoother and quieter with the pump operating. Seat of the pants difference was hardly noticiable with pump on or off. The plus was no P1093 which could easily be set before the sump/ Airdog installation.

I'll let Nate fill you in on the rest as he drives the truck everyday and can better explain the before and after. Here are a few of our pics.
http://www.dieselinnovations.com/images/dmax_sump

Powerstroke,

That look's like a good idea.

Did you just block off the factory pick-up fitting?

How much does that sump stick below the tank? 2 or 3" ?

With a sump like that your tank will never have any sediment or water in it cuz it will get sucked out right away and with a good filter/seperator it will keep the tank clean and no chance of one day ingesting a large quantiy of crap all at once.

Where did you get that sump at? Is it a Holley or Fuel cell manufacturer's or did you make it yourself?

Have you tried experimenting with hard braking situation's or steep down hill's and low fuel level's too see if the sump which you located towards the rear of the tank will become uncovered and possibly stall the engine when you might need your brake's the most?

I wonder if you can somehow T the factory pickup and the new sump pickup lines together so you have the best of both world's but somehow put a valve in place so if one of the pickup's sucked some air it would close and stop the introduction of air to the system?

I see the top of your pickup assembly has some type of canister between the fuel inlet and outlet tube's, do you know what it does? I don't think I have that on my LB7 engine, maybe it has something to do with the code's that the LLY's are getting. Or is it just the new vent assemblly for the LLY's.

Also noticed that the line's on top of the unit are metal in your picture's, I'm pretty sure the LB7's are plastic.

Keep the picture's coming they are worth 1000 word's

DD

DD- There will be more pics tomorrow showing the clearance.

The sump is from the DI Powerstoke fuel system and are a DI exclusive.

We have driven the truck in just about every possible way you can. Hard braking, hard accell, normal driving, etc. The tank has also been ran from 1/2 all the way down to E where it is now. Zero problems to speak of. We have not ran the tank up or down any steep inclines though.


We also ended up modifying the airdog mounting bracket for clearance issues as it did hang fairly low. The sump actually still sits higher than the airdog. The sump is a non issue as far as clearnce goes.

DSTRBD
I saw the sump in the picture's on your web site as part of a larger fuel pick up system for ford truck's, do you sell just the sump seperate?

I can see how the height of the sump could be a non issue for a ford but us stock Chevy's are vertically challenged and it might make a difference. If you could find out the height when you have time I would appreciate it.

Thx

DD

Yes, the sump can be bought seperately. Here (http://www.dieselinnovations.com/images/sump/index.html?pic=ford_regulator_cap_shims_large.jpg) are a few more pics of it.


We will take pics with a tape measure to show the clearance tomorrow.

I had a feeling that this was where you two were going with this. One in Texas one in Minn. working on it together? :eek:

I had considered the DI sump when I first started looking at the system. It looked like a good idea for racing. I just wasn't willing to modify my tank by cutting a hole in the bottom of it and then going to a dealer and expecting them not to say anything. I also had concerns about my legal liability should the sump get ripped out/off during a traffic accident.

Still it is an option for some. :ro) Thanks for the hard work guys!

Trippin- I realize there are alot of guys that wont be willing to drill a hole in the bottom of their tanks. However, your concerns are the same as the 7.3L guys when the sump was first released. At first everyone wasnt sure, but as more and more started being run, people began to see that it works very well. The sump as far as clearance is a non issue. It also works flawlessly for daily driving. I say that from experience with the 7.3L as we are still testing the LLY. This seems to be a good fuel system solution, but probably not the best solution for everyone. I will be taking the truck back to MN for a while so I will be able to see how it performs with various tank levels.

The reason for the sump was to move the pickup away from the return and the filler neck where the airated fuel was being dumped. The filler neck dumps right on top of the stock pickup so when the tank is run low, the stock pickup gets mostly bubbles from the airdogs return. Now with the sump, there are little to no visible bubbles in the airdog's return to the filler neck.

What do you think happens when the truck is parked on a hill or going down a hill with the sump system? Wouldn't the sump become uncovered?

Like I said before cutting the tank was not something I thought most customers would be willing to do. With the injector failure problem already there, this would give GM a way out so to speak as it's in clear site that the fuel system has been modified. If you plan on towing in the mountains you will be in trouble. Let's look at what will happen when your going down hill with a trailer on the back fully loaded. The fuel will run to the front of the tank and uncover the sump. Once the motor stalls you've lost power steering and power brakes...................... not something I would want. The best position for a sump is dead center in the tank just for this reason. It gives the best possible location for all conditions. A truck with a long box will be worse than a short box truck. There is one other small thing, it's completely illegal to do. The Federal Motor Vehicle Safety laws prohibit the use of a fuel container with a sump on all motor vehicles that are use on highway. The supplier/manufacture has to provide a system when in an accident will contain fuel with broken lines, this would never cut it. While fine for a race car, I would never recommend it for any street driven vehicle, just to much risk involved. I hope that someone has a real good insurance policy to cover this type modification.

The same thing that would happen with the stock pickup going up hill if the levels were the same.The demand for fuel going down hill while on the brakes is almost the same as idle.I understand your concerns as we went through this sometime back on the Fords.What we found was that we could run the fuel level as low as you could with the stock pickup.I added pictures of the tank after installation.You will see the e brake cable holder hangs down lower as well as the reverse hump on the exhaust system.The drive shaft angle is also quite a bit lower than the sump.The way I look at it if you manage to rip the sump off of the tank you have bigger concerns to worry about as there will be much more damage to the rest of the truck.If some one were overly concerned they could fabricate and add a skid plate below the sump.

http://www.dieselinnovations.com/images/dmax_sump

The same thing that would happen with the stock pickup going up hill if the levels were the same.
Except that the stock canister holds more fuel than your sump. On an engine that is trying to maintain 4,000 psi of fuel pressure at an idle and bypassing the rest back to the tank, where as a Ford is ?????

I'm not trying to be combative, just drilling down to a solution for everybody. :D

Good point Guy.

Like I said before cutting the tank was not something I thought most customers would be willing to do. With the injector failure problem already there, this would give GM a way out so to speak as it's in clear site that the fuel system has been modified. If you plan on towing in the mountains you will be in trouble. Let's look at what will happen when your going down hill with a trailer on the back fully loaded. The fuel will run to the front of the tank and uncover the sump. Once the motor stalls you've lost power steering and power brakes...................... not something I would want. The best position for a sump is dead center in the tank just for this reason. It gives the best possible location for all conditions. A truck with a long box will be worse than a short box truck. There is one other small thing, it's completely illegal to do. The Federal Motor Vehicle Safety laws prohibit the use of a fuel container with a sump on all motor vehicles that are use on highway. The supplier/manufacture has to provide a system when in an accident will contain fuel with broken lines, this would never cut it. While fine for a race car, I would never recommend it for any street driven vehicle, just to much risk involved. I hope that someone has a real good insurance policy to cover this type modification.:badidea: The thought is great but when I was up at the dealer today I asked because they know about my P1093 issue and they said, it would void the warranty if a GM rep saw it on the truck. I called the insurance and asked the what if someone did this and what if this happened, basic answer was they wouldn't pay and the owner probly would end up with more Censored than they ever wanted. I'mm all for a easy fix but as I psoted before my tank is already lower than stock and this would be asking for trouble. I agree with trippin - keep talking and we will find a workable , insurable, no warranty voiding fix. JM2C

Garage owners liability insurance will not pay either if a shop was to do that mod and something happened. This whole idea of a separate sump is not good.

Steve

Can you point me to where your tuners are emissions legal in all states and where it states that removing the speed limiter is not a liability on your part.
Might as well show us which exhaust systems allow us to legally remove cats and legally install aftermarket air intanks systems.Oh and before you answer will your fuel system be EPA certified?

Steve makes you sign a waiver for his tuners and he doesn't have a cat delete pipe for his exhaust systems.

If you plan on towing in the mountains you will be in trouble. Let's look at what will happen when your going down hill with a trailer on the back fully loaded. The fuel will run to the front of the tank and uncover the sump. Once the motor stalls you've lost power steering and power brakes...................... not something I would want. The best position for a sump is dead center in the tank just for this reason. It gives the best possible location for all conditions. A truck with a long box will be worse than a short box truck. How about running a sump fore and aft and teeing them together?

Of course, if running a sump both fore and aft you run the risk of air being drawn in if either inlet becomes uncovered with fuel....

If its sucks any air(it will suck air before fluid) it would hickup the same and or die. Youd need some sorta valve in there.

I signed a waiver and my program is for off highway use only. And I wouldnt dare dream of driving it on the street. If I did no one would be able to tell and i can go back to 100% stock in a few minutes if need be. But sice I dont drive it on the street........

Now what would be trick is a bladder set up. But that would creat so many PITA things to deal with it wouldnt be funny. But your truck could stay running even if it were on its lid:eek:

The modifications we are testing will not void the EPA requirements and it also does not violate the Federal Motor Vehicle Safety standards. I've been quite about a lot of our developments just for this reason. It takes time to develop them and make them reliable and safe. Something for a race car doesn't always work well on a street vehicle and there are parts we will not make just for those same reasons. There is a reason we require a wavier for the Xtreme programs. I guess you have not looked into what would happen to you and your family if your fuel system was found to be illegal and someone was killed as a result of an accident. I have and that's a risk I'm not willing to take and the insurance cost to cover it means you could never sell it as no one would be willing to pay the price. Ever wonder what cutting a hole through a plastic tank does to the strength of it for accident protection. How about the expansion rate of the aluminum sump verses the plastic tank? Do you think the aluminum sump would allow the tank to perform the same as before it's installation? These are just a few things that need to be considered, but I'm sure many of you remember the GM fuel tank lawsuits over the old truck tanks that were outside of the frame rail. Although GM ended up winning most of them it cost them millions.

You can up with all kinds of reasons why something want work if you look hard enough.Do most you you drive around trying to see how low you can go before picking up air with the stock system?
When you find it do you repeatedly keep doing it again and again?

Another way would be to extend a pickup toward the back of the tank while still attached to the factory sending unit.I'll get back with you on that one.

It's not always about reasons why does something not work. What you need to do is learn to go do a little more testing in all conditions before bringing something to market that is easy to see will cause problems and safety issues as well.

Another way would be to extend a pickup toward the back of the tank while still attached to the factory sending unit.I'll get back with you on that one.
If your going to get rid of the bucket(and its anti stall design) then you might as well just leave it in its same place and hack the hell outa it so it fule can just pour in. Moving the PU from the center to the back would just alow you to run the tank a bit lower and not starve it under launch. Moving it back a bit might allow you to launch with less fuel but I dont think thats something that most guys are shooting for.

I run with a pretty full tank. Other than extra weight I think running with a pretty full tank is a good idea and dont see a downside. More stable fuel temp, less foaming I would think, less likelyhood of sucking a gulp of air.

The sump works quite well and the safety part can be argued all day long about the nurmerous mods we all do.No the sump is not for everyone just like different makes of vehicles appeal to different thoughts of what is best for the intended application.

I am used to most of my customers that pay to play and usually don't go back to the dealer trying to warranty something they broke.Like I tell people all the time if warranty is a big concern leave it stock.

You forget your talking to a bunch of duramax guys.;) Most dont have a problem paying for something we screw up for the most part but these pesky injectors has every one so darn paranoid! People assume they are going to have to have thier truck in for it once and I would be pissed if GM made me foot a big bill for something that wasnt my fault and known to be a POS!

True most of the hard core would give up some drivability but if there was a way to have our cake and eat it too then that would be even better.

Ya,forgot about you guys having injector issues.

The sump works quite well and the safety part can be argued all day long about the nurmerous mods we all do.No the sump is not for everyone just like different makes of vehicles appeal to different thoughts of what is best for the intended application.

I am used to most of my customers that pay to play and usually don't go back to the dealer trying to warranty something they broke.Like I tell people all the time if warranty is a big concern leave it stock.

There is a legitimate significant issue with warranty on a 40-50K truck that you are making payments on.

Personally, I break it racing, I pay for it. If it was a design flaw (injectors being one) I still expect them to honor the warranty. I melt a turbo running 1600 deg, I'll buy it. I fry a stock trans running stoopid HP, I'll fix it.

Don't downplay the warranty issue with trucks that are mostly 2 years old or less. The easier it is to "hide" mods for routine service visits, the better off you are, and it certainly comes into play when people select modifications.

PSS - Everyone with high pressure injection is running into issues. Dodge, Ford, and Chevy.

I have been away for a few days, good to see this thread getting somewhere.

I had some ideas while on the road. Cut the original pick up tube above the basket. Run a separate line into the bottom of the tank. So know you are sucking fuel from the basket and also from the bottom of the tank. If you suck air, the FASS, Preporator 135A or the Air Dog should take this air and return it to the filler neck, They should never miss a beat depending on how much air you were to suck. I will find out very soon.

For clarification purposes, the basket collects sloshed fuel. So if you are running straight up a hill for extended lengths you will still have fuel. So even though the fuel is in the back of the tank, one little bump and the fuel gets sloshed. The basket then grabs this fuel and keeps it. So everytime you create a slosh big enough to make fuel pass by the bucket, you are filling the bucket. Pretty neat idea and critical for a vacum system that must not suck air. Lift pumps are not as sensitive to sucking air especially if you have a water separator and filter for reserve fuel storage.

I think there are different fuel problems happening and they all have different symptoms and different solutions if you look very close.

Any super big tune with injectors could drain the basket regardless of whos lift pump you use. There is no return fuel down the factory return line and not enough fuel can come into the basket.

I think connectiing a pickup out side the basket in conjuntion with the factory basket is the best way to go. The only catch is dropping the tank and installing a tee on the top half of the factory pick up tube or trippin pickup for that matter. Maybe a second basket will be required like Max said?

When I get the tank out, I am sure it will throw me a few curve balls.

One of these
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=112587&prmenbr=361

in conjuntion with the factory basket should be fine.

It really shouldn't matter though, only one Air Dog 80 has problems that I know of . Reduced demand on basket.

Bronco

I was thinking about a new bulkhead fitting about 5/8" at the top of the tank with a new pickup tube going down to with in an inch or so of the bottom of the tank for a new pick up spot and then another 5/8" bulkhead fitting closer to the front of the tank for a return tube that extends down to the bottom of the tank also, that way any returned fuel from the FASS or Airdog would be returned with out much sloshing like it might do going down the filler neck.

Gmpartsdirect has the sending unit assembly for $235 or so and $40 shipping.
I ordered a new sending unit and will modify it with the Trippin/DieselTech Billet pickup and larger fuel fitting's that I have.

And then a new Supertank some time soon I hope, to install everything into and I'll see what happen's

I was going to try running the pickups seperate to see which one would suck air first on a low tank of fuel going up or down a hill.
And puting a T between the two pickups sounds like a good idea too.

As long as you don't suck air for an extended time on either pickup the pump should be able to reprime quickly and keep the fuel coming.

DD

PS

Problem Child started a thread a while ago about installing those Holley pickup's in his tank but never said how it turned out. I brought the thread back up and asked him about it but he hasn't replied yet

Here's the link

http://dieselplace.com/forum/showthread.php?t=18348

Update:

Installed a Carter pump and the Trippin pickup.

The "laydown" has disappeared!@

BUT...

I threw a P1093 on the way home by just doing a short 5 second burst of acceleration after a fresh PCM DTC erase.:(

The P1093 is not the same thing as the laydown.

I found out why mine was doing it.. it was hitting that speed limmiter. forgot to recalibrate my slicks. i will be prepared next time i go to a 1/4 mile. I got the fass and the rev limmiter raised

Set a P1093 because of a speed limiter or calibrating the slicks??? Damn, all this time I was thinking it was a fuel issue.

Not sure what actually causes the 1093's yet.

The "easy" solution will be done through the PCM, it's probably just 2 bytes of code.

But which 2 bytes out of 1,000,000 bytes is the question... :eek:

Set a P1093 because of a speed limiter or calibrating the slicks??? Damn, all this time I was thinking it was a fuel issue.
IN my case it was laying down at top end without 1093. which was because of the speed limmiter. i was not throwing 1093's. i thought it was a fuel issue. guess not!

I set a 1093 code today staging my first run at the dragstrip ( I have an LB7 '04 ). I was building boost on the line while I was paired with Trippin. I think I saw Guy with a Silver Birch Duramax voodoo doll in his hands and he was poking pins in it. :eek: My ses light came on while I was building boost on the line. I was taken back by this phenomena ( it's called having your thumb in a dark place ) at which time Guy takes off and I heard " :muahaha: " :eek: I think this may be a first as far as setting this code in the staging lanes.
mike

I understand that Guy will resort to almost anything to win. Voodoo doll only if he cannot find the fuse. Today he even enlisted the assistance of the track steward to create an excuse for him before we even staged...

I understand that Guy will resort to almost anything to win. Voodoo doll only if he cannot find the fuse. Today he even enlisted the assistance of the track steward to create an excuse for him before we even staged...
):h ):h ):h

That was a great run you had Mr. Magu. You beat me by 4 tenths! :ro)

I set a 1093 code today staging my first run at the dragstrip ( I have an LB7 '04 ). I was building boost on the line while I was paired with Trippin. I think I saw Guy with a Silver Birch Duramax voodoo doll in his hands and he was poking pins in it. :eek: My ses light came on while I was building boost on the line. I was taken back by this phenomena ( it's called having your thumb in a dark place ) at which time Guy takes off and I heard " :muahaha: " :eek: I think this may be a first as far as setting this code in the staging lanes.
mike

Look's like Guy's Karma ran over your Dogma. :eek:


Have you noticed that I play with a Predator in the truck every pass? Even when I'm not even RUNNING the Predator? ;) Most the time, it's under my front seat.

I reset the DTC's even if they are clear already for added insurance.

If you do throw a 1093 without a DTC reader handy, turn on/off engine 3 times for 5 seconds each time. Will reset.

Do you guys think the 1093's are ambient temp. related at all? This may be a dumbass theory, but the only time I've thrown a 1093 was the warmest weather I've driven in since installing the high tune with the Predator.

Knock on wood, I've never set one in cooler weather regardless of the truck's temp.

As I mentioned before, I was also seriously low on fuel. Luckily, I've only ever thrown it once.

Do you guys think the 1093's are ambient temp. related at all? This may be a dumbass theory, but the only time I've thrown a 1093 was the warmest weather I've driven in since installing the high tune with the Predator.

Knock on wood, I've never set one in cooler weather regardless of the truck's temp.

As I mentioned before, I was also seriously low on fuel. Luckily, I've only ever thrown it once.Consider yourself very fortunate. I've set it off all times of the day; morning(warm), evening(cold), mid day(hot), you get the point. I've even set it off just normal driving going up a slight grade. The 1093 sure isn't shy around me. I do recall the first time I set it off; Feb. 12, 2005 making a right turn onto the onramp of the freeway. Nailed it, got sideways, let off, nailed it, merged, cruising speeds by then, check engine light! Got home, 1093!!! So it began, will it end...

PS-Fuel level was no less than 1/2 tank.

Finally got around to reading this thread. A few things to add. Maybe BS, so go easy on me.

GM probably returns the recirculated fuel to below the fuel level in part to reduce surface static buildup. In the petroleum industry, it's bad safety practice to fill a tank from above the surface. The splashing creates static. Since the fuel (like all HC's) does not cunduct well, it does not get continuously grounded through the piping. You can get an island of static which sparks when it floats near to a ground. Yes this has happened. Normally diesel tank vapor is below LEL, but it can get hot enough sometimes in special situations, ask TWA.

If I understand it correctly, inside the tank there is a cup with one or more scupper valves near the bottom. Fuel is drawn from the cup and recycle is returned to the cup. In a high-g situation, with a low tank, the cup stores a bit of fuel for the engine, until the fuel sloshes back and either refills the cup by overflow or through the scupper valves.

Seems like any device that pulls extra flow from the cup and returns it elsewhere would make the problem worse.

I'm not sure how the fuel in the stock system is getting aerated. If the cup starts with clear fuel, and returns clear fuel to below the interface in the cup, how exactly is air getting in? (assuming no air leaks to the low pressure side).

Seems, the best place for the fuel pickup cup would be the rear of the tank like drag racers do. Then at least the scuppers would always have level to let into the cup.

How about this...install a fitting allowing fuel out at the rear/bottom of the tank. Run a pump (from whomever) from the fitting to the return line to the cup. Use a switch (for special occasions) or activate it by RPM or high boost. Then it would help keep the cup full all the time. It might also keep the level higher so any foam would rise above the cup rim.

I'm not religous, but to all you guys working on this problem, may your cup runneth over.):h

Hi all,

Is it possiable that code does not mean low pressure but over pressure? as it only comes on after the wot or is that just the delay? just a question...

Wild Ass Conjecture: (DO NOT ASSUME THIS TO BE TRUE)


Here's what I think causes the P1093:

On a stock fuel curve it "commands" a given pressure, a signal is sent, pressure builds, pressure is checked, and all is well.

This works fine for a 1/4mi pass, because it might not check the rail pressure unless there is a commanded change, and you are at full pressure, so it doesn't check.

Now when you are cruising on the freeway and nail it, all is still fine because there is probably a "delay time" built into the program to allow the pressure to build before it checks.

Now put in a big tune:

At the track, same thing. It commands to full pressure and doesn't need to check.

But on the highway, you are cruising with low commanded pressure, then nail it, the ECM program tells it to hit the pressure full blast, at the same time the fuel flow is higher than stock so it takes LONGER to build to the requested pressure. It checks, finds the pressure is not building as it should, and assumes a fuel leak, and limps. Since the delay is set to what stock consumption is, a bigger program needs to change that delay value also, but doesn't.