Who all is running a bypass reg on their lift pump set up and how do you like it? Ran into any that gave you problems or any that you didn’t/wouldn’t run for any particular reasons?

I plan on running a by pass reg before the factory fuel filter and running as little psi through the factory filter edu as possible. 5psi or maybe a few under that. Most regs I see have a min setting of 3 psi. I’ve seen lotsa potential regs but just wondering what experience you guys have had with running diesel through what ever you are running. Any other particulars of your set up would be appreciated too. And if you are running any pump that you really like, although I am thinking I have one narrowed down.

Also were are you dumping your fuel back into? The filler neck? I was thinking puking it back into the pick up point in the tank(the little bucket deal) but really fear aerating the hell outa the fuel.

The wheels are churning, I have planshttp://www.dieselplace.com/forum/smileys/Wink.gif, one of these days my truck will actually be reasonably quickhttp://www.dieselplace.com/forum/smileys/Geek.gif

As always thanks in advance. http://www.dieselplace.com/forum/smileys/Approve.gif http://dieselplace.com/forum/smileys/Rock%20On.gif

Also remeber reading something about if you are running a lift pump puking into the filler neck you can fuel your truck while its running? Any truth to this? Or am I dreaming again? That would suck, oh well, the price we pay for powerhttp://www.dieselplace.com/forum/smileys/Cool.gif

You can eyeball my setup at JK's get together if you are going to be there.

Dont think I will be making the road trip this timehttp://www.dieselplace.com/forum/smileys/Disapprove.gif

Dont think I will be making the road trip this timehttp://www.dieselplace.com/forum/smileys/Disapprove.gif





Gee, and I was planning to slip Barney Fife some valium so he'd be more easy going during the weekend...

Well if you are inviting and going to run some interference so I dont get another ticket I may have to make a road triphttp://www.dieselplace.com/forum/smileys/Approve.gif You be able to turn up my juice while I'm there? Still down on powerhttp://dieselplace.com/forum/smileys/Disapprove.gif and I dont think I could handle being stock for any timehttp://www.dieselplace.com/forum/smileys/Thumbs Down.gif

Well if you are inviting and going to run some interference so I dont get another ticket I may have to make a road triphttp://www.dieselplace.com/forum/smileys/Approve.gif You be able to turn up my juice while I'm there? Still down on powerhttp://dieselplace.com/forum/smileys/Disapprove.gif and I dont think I could handle being stock for any timehttp://www.dieselplace.com/forum/smileys/Thumbs Down.gif





Can do the Juice on site any time...

I tried using the Holley “Black” fuel pump with their regulator (non-bypass). It lasted exactly one month and it quit working. I called Holley and talked with their tech people and they said that it was the correct regulator to use, and the reason for the pump failure was due to the diesel fuel. Their stuff is not diesel rated. I had the Stanadyne FM100 in stock so I threw it on. The Stanadyne runs unregulated and makes a constant 6 PSI measured in the line out of the factory filter. It will drop down to 5 or 4 under hard accelerations, but I have never seen it go below that. I installed the Racor fuel filter on the frame rail under the truck and have the FM100 after that. The FM100 is doing the job and is quieter than the Holley was.

The one thing about lift pumps on a Duramax that alwys gets me is???


The fact that the Duramax has it's own regulator and return line. This means that regardless of what and and how we add, there will always be an uncontroable leak in your fuel system. Chew on that.

Bronco,


Calling it a leak is a bit off base. The returns are present in the system on the high pressure side, from the fuel junction block, the pump and the injectors.


The returns mean pretty much JFS when it comes to maintaining a positive supply of fuel to the pump on the low pressure side.


I know there has been a ton of debate on whether they help or hurt or whatever. All I know is that the Bosch spec calls for a lift pump and that is good enough for me. Have I seen any gains on they dyno? Nope. I do know that my fuel filters are being used to their utmost capacity and that I won't have a delivery problem on the low side.


Like Trippin says, don't shoot the messenger, I am just giving you my results. http://www.dieselplace.com/forum/smileys/Approve.gif

I have decided that for my application some sorta lift pump is required. I was wanting to run a higher pressure up to the factory filter but wanting to run as little psi through the factory filter and edu as possible in the 3-5 psi range. With a stout pump running 15-20 psi or so and a good reg it should have absolutly no problems maintaining a 3-5 psi outlet with very minimum pressure drop and as long as it stays positive to the low pressure pump I believe thats all I need.


I think I may be trying to over-enginner this whole system though but I guess its my nature, when in doubt over kill.


Maybe i need to go the KISS route.....


Man do i try to make things a PITA at timeshttp://www.dieselplace.com/forum/smileys/Embarrased.gif

I run unregulated 8-9 psi on mine at present. Drops to 3-4 under load depending on conditions. The OEM pump regulator is my bypass, and I have plenty of volume available

BTW The holley didnt like diesel? I thought there were a few guys running the holleys? One thing about holleys with gassers is they are fairly cheap and rebuildable albiet noisy as all hell. What died on the holley? Could it be fixed with one of thier rebuild kits?


Edit #2 did some searching on the fm100's. Duno were i got a 6.5 part?http://www.dieselplace.com/forum/smileys/Embarrased.gif I just remembered hearing of em but couldnt remember were.


Think KISShttp://www.dieselplace.com/forum/smileys/Geek.gifEdited by: ratlover

I see no valid reason to regulate pre OEM filter or EDU if you are under 15 PSI. JMHO.

was planning on 20 or so psi with the set up I was thinking of.....even 15 psi through the factory edu gives me the willies wether it should or not.http://www.dieselplace.com/forum/smileys/Confused.gif


But 6 aint nothing, heck I think i pee with more pressure than thathttp://www.dieselplace.com/forum/smileys/Ermm.gif


Might just get me my pre and a fm100 and see what happenshttp://www.dieselplace.com/forum/smileys/Confused.gif

My EDU has been holding 12+ for over 8,000 miles. I think it could hold 30 PSI with ease, probably much more than that too.


Plumbing your bypass before the EDU will be more difficult too, unless you are planning on replacing the line all the way from the tank. I don't see any real benefit there either since there is enough fuel using the stock lines to make 700+ horsepower.

Somebody have a spare EDU laying around. Pressure that thing up and lets see what gives. I think it will hold 30psi no problem.

I have been scoping out a pump and regulator that will certainly do the job but $500 is a little to steep. It has an8 fiting on the pump and would fit inline right on the frame. The regulator you could return it back through the OEM returnline. I think the regulator is adjustable from 5-15 psi. Another unit that I have on hand is a Racor that wil do 10 psi constant but I have not done anything with it yet. The thing I don't like about that is it has and internal bypass.





GregEdited by: LanduytG

I dont know if I like returning to the factory return?http://www.dieselplace.com/forum/smileys/Confused.gif Could this cause problems? Too much fuel to the return?


500 is kinda steep but if it does the job? and has a nice easy clean install.

I would not and did not splice into the factory return. I don't know how much pressure the factory return line is carrying but you want no restriction on return lines. If your bypass is carrying more pressure than the stock return line and you hook the two together you have an instant problem.

thats my worry, unfounded or not since I dont know much about the systemhttp://www.dieselplace.com/forum/smileys/Confused.gif

Any worries about bypassing the stock fuel cooler when not using the OEM return line?

The bypass regulator will have it's own line going back to the tank so the return loop won't have anything to do with the stock return line. You still need the stocker in place so you will have the cooler unless you are trying something really nutty with your line routings.

Your not worried about the heat that the lift pump is creating? Without going through the cooler, you are putting the heated fuel back into the tank, and the risk of condensation or bacteria growth have increased.

Your not worried about the heat that the lift pump is creating? Without going through the cooler, you are putting the heated fuel back into the tank, and the risk of condensation or bacteria growth have increased.


Amric,


I have monitored the fuel temp before and after the lift pump install and I can't tell any difference. The system picks ups a ton more heat from where the lines are routed on the engine and from the EDU. I have considered adding an additional cooler on they bypass loop but I don't think it necessary.


With the right kind of pump heat won't be a big deal anyway. On my last trip the pump was only warm to the touch after six plus hours of continuous running. No appreciable changes in water in the filters or crud in the filters for the last 8K miles either.


I will tell you that the Mallory Comp 140 is not a good pump to go with unless you enjoy rebuilding it about every 6K miles.....

Also,


The stock return line is moving a great deal of fuel. It can empty my five gallon race cell in a matter of minutes so I think that we are getting enough flow to compensate for the additional bypass loop.


JMHO though. Others results may vary. http://www.dieselplace.com/forum/smileys/Embarrased.gif

Bronco,


Calling it a leak is a bit off base. The returns are present in the system on the high pressure side, from the fuel junction block, the pump and the injectors.


The returns mean pretty much JFS when it comes to maintaining a positive supply of fuel to the pump on the low pressure side.


I know there has been a ton of debate on whether they help or hurt or whatever. All I know is that the Bosch spec calls for a lift pump and that is good enough for me. Have I seen any gains on they dyno? Nope. I do know that my fuel filters are being used to their utmost capacity and that I won't have a delivery problem on the low side.


Like Trippin says, don't shoot the messenger, I am just giving you my results. http://www.dieselplace.com/forum/smileys/Approve.gif





BMDMAX,


No shooting of the messenger. you are correct, I do not understand all of the aspects of the factory return system. For example, how much fuel it returns, why it returns it and if it a mechanical or computer controlled amount. I was mainly trying to illustrate, that it is hard to design an aftermarket regulator/lift pump when upstream there is a leak in the system. You could set your pressure one minute and the next it isn't keeping up because the factory regulator is just bleeding off more of the pressure you added?


I totally agree that a lift is a good idea for several different reasons. A few are not open for debate.


1. If you run out of fuel, a lift pump will save the day.


2. Ensures that your fuel filters are full from bottom to top on all sides.( Maximum filtration and life span.)


3. Ensures no stalling from air pockets and vapor lock.


Not trying to argue the lift pump, just curious, how to size the pump and maintain pressure.

Not a problem maintaining pressure as long as you have enough suppy to start with. IMHO you need a pump that will deliever at least 60 gpm at 10 psi. That way if you want to maintain 5-7 psi you will have plenty of room to work with. You will be returnin more fuel as the motor demand is less and returning less fuel when the motor demands more. The OEM fuel reurn acts as cooling for the the fuel system. The reason for the fuel cooler is because of the high pressure a common rail system produces. The higher the pressure the more heat it will make. As for cooling the lift pump you have such a small amount of pressure increase you would never see a temp rise.





Greg

Is anybody with a regulated return system using boost referancing ?.

carterkraft, it certainly couldn't hurt. Makes sense to have more fuel/pressure available when under boost, although it wouldn't be directly tied to the injectors it will ensure the filter doesn't run dry. Edited by: GSXRTURBO1

Mine has the port setup for it but I have never bothered to hook it up. It will reference one PSI for every pound of boost. Might be useful but I am maintaining positive pressure through the entire run anyway.

May be cool but not needed and i dont even think there is an off the shelf reg that would work. Most use a 1 to 1 ratio like was said. Thats pumping 30 psi down streamhttp://www.dieselplace.com/forum/smileys/Shocked.gif You would almost have to work to make such a system function, much simpler to just use a regular reg(preferably bypass).


Besideds.....IMO all you need to do is to maintain a positive pressure through out the system. Pressure drop dosnt mean anything IMO as long as the suction side of the lp pump is seeing any positve pressure even if its just a few inches of WC. Just my theory, no actual testing to back it up so take it as it ishttp://www.dieselplace.com/forum/smileys/Geek.gif