Been seeing a good bit about Lift pumps.


Being VERY new to the Diesel I am not familiar with the different Mfg's and types that can be used.


Can anyone give a list of the different types. Will the ones from the 6.5's work?

Mike,


There are quite a few options when it comes to lift pumps. It really depends on what you want to accomplish. Figure that out, and make your decision on a pump from there.


Yes, a pump from a 6.5 will work, several members use them today with good results.


There are two main reasons to add a pump: removal of air in a post-oem filter setup or pressurizing the fuel supply to aid in high HP, high fuel demand situations.


The 6.5 pump will do a good job at solving air problems with a post-oem fuel filter install. It becomes a restriction point for a high HP setup.


For a high HP setup the options get pretty varied. You have to take into account flow rates, the PSI you want to hold at the low pressure side of our injection pump, where you will regulate, line sizes, if fuel will flow with the pump off or if it dies, how you will wire it including the use of an oil pressure switch, etc.


It can get overwhelming pretty fast. I am still mulling over options and I can't definitively say that it is worth the effort yet. It has not been seen on the dyno but others say it really helps on the track.

One thing I learned about lift pumps yesterday from ATS. I told him several members of the Place have reported there pressure dropping to 0 when running high HP or load. I told him, the members stated there trucks ran fine. He said that ATS people have noticed the same thing. No performance issues. HE THEN CAUTIONED ME! He said the system was designed to have 30-40% return flow for lubricating and cooling. He said you never want to put a diesel in a situation where all of your fuel is going to the injectors. Made me think!


He also mentioned that CLINT from ATS has noticed very strange things happen to his DMAX when he prefed the system with more than 7PSI. Made me think! He said a guaranteed 5psi at all times and all conditions is the way to go. Basically run 7 and maybe drop to no lower than 5 under racing/load situations. GM has to have specs printed somewhere for the factory Min./Max pressure. All you would have to do is duplicate these specs. no matter what your situation and you will be fine. There was a pressure question posted in the ask the tech section just yesterday. I am anxiously awaiting a response. I would like to know what the factory system was designed to do. I just want to mimic the factory no matter how many fuel filters/HP/Sled Pull/drag race/ 25000 LB horse trailer. My Fass is coming to me preset at 10PSI and I am getting concerned. Edited by: Bronco

The one key thing that stands out is that without a lift pump, we have air in our fuel, and with a lift pump, we do not.

Kennedy:


What kind of Lift pump are you running, I am going to order the Mags to get the lead out(Metal). Now I am thinking about air, seems like this would be the last item to worry abouthttp://www.dieselplace.com/forum/smileys/Confused.gif, I value your opinion! Any Worries about Warranty issues?

Gm has no specification on a lift pump as they donot use one. What we have found is that the Bosch Common Rail High Pressure pump used on the Dodge and the Duramax are basically the same unit. With that in mind looking at the Dodge specification gives a starting point, 13 -15 psi. Now the Dodge does not run the fuel through the EDU like the GM does so we are a little concerned as to how much pressure the EDU will take without starting to leak. Many members have been running 8 psi with no trouble at this point in time. We have setup a test stand to pressurize and EDU on the bench and will let it sit at 10 psi 24 hours a day for one month. If after one month we find no leaks we will raise the pressure to 15 psi and start the test again. If everything passes at 15 psi we will call it quits as that's the high side of the Dodge specification.


As far as problems above 7 psi we have already been above that with no problem to date so I would thing ATS's problem was from something else.

The one key thing that stands out is that without a lift pump, we have air in our fuel, and with a lift pump, we do not.











How does a lift pump reduce/eliminate air in fuel?

srode


Duramax has a pump that sucks the fuel from the tank there fore when fuel is being pulled by vacum there can be cavitation. With a lift pump you are pressuring the fuel to the system and only way that air gets in is if you run out of fuel. you will notice a smoother running engine and maybe it's me but mine seems quieter. I run the fm1oo stanadyne with a filter water seperator, but if you are going for the big ponys like a lot of the fellows do, there are better pumps out there. You should not need a lift pump unless you add extra filtration in the post position. Nick tane works great when mounted close to fuel tank, But if you put the monster Kennedy in the post,I suggest a lift pump. Hope this helps


GenoEdited by: geno

Diesel Tech wrote:


As far as problems above 7 psi we have already been above that with no problem to date so I would thing ATS's problem was from something else.


The details of Clint's problems were not explained to me. It was second hand from an employee. I did wonder if his other performance mods. could be causing a problem inconjuntion with the high pressure? Sdaver already documented 7-9PSI for 24kmiled and others have run 10psi at the track. Brad from Fass states that the gears on the pump will not allow any extra fuel to flow through them once the supply demand has been met? If the EDU being tested proves not to leak could there still be other operational issues related to excessive pressure?

We have setup a test stand to pressurize and EDU on the bench and will let it sit at 10 psi 24 hours a day for one month. If after one month we find no leaks we will raise the pressure to 15 psi and start the test again. If everything passes at 15 psi we will call it quits as that's the high side of the Dodge specification.


This is a good starting point. It will estabish one data point. The EDU (or FICM ?) is cycled over temperature too. There are also manufacturing tolerances involved plus a vibration spectrum to deal with. Establishing this one data point will be interesting.


For those like myself who might run a lift pump for reasons other than making a lot of HP, this will establish an upper bound. I would back off a considerable amount from this point and consider it good to go. For those on the max HP path, you are pushing the envelope anyway, so go for it!Edited by: OC_DMAX

srode


Duramax has a pump that sucks the fuel from the tank there fore when fuel is being pulled by vacum there can be cavitation. With a lift pump you are pressuring the fuel to the system and only way that air gets in is if you run out of fuel. you will notice a smoother running engine and maybe it's me but mine seems quieter. I run the fm1oo stanadyne with a filter water seperator, but if you are going for the big ponys like a lot of the fellows do, there are better pumps out there. You should not need a lift pump unless you add extra filtration in the post position. Nick tane works great when mounted close to fuel tank, But if you put the monster Kennedy in the post,I suggest a lift pump. Hope this helps


Geno





Geno, thanks for the explanation..... On the other hand, unless there is already air in the fuel or unless there are air leaks in the fuel system allowing air in while the fuel is under vacumm between the location where the lift pump would be installed and the factory pump is located, the only vapors that show up during cavitation should be diesel vapors. Once on the otherside of the factory pump, the diesel vapors should go back to fluid state. Still doesn't make sense to me without an air leak that there should be any air added without a lift pump. Guess I won't need to worry since I have a stocker with Nictane kit, but still curious.

Vaporization...

Okay let me get this straight. If I want to add a Nicktane do I have to add a lift pump? http://www.dieselplace.com/forum/smileys/Confused.gifhttp://www.dieselplace.com/forum/smileys/Confused.gif

A lot of guys out there running with out the pump, I would say NO


Geno

Okay let me get this straight. If I want to add a Nicktane do I have to add a lift pump? http://www.dieselplace.com/forum/smileys/Confused.gifhttp://www.dieselplace.com/forum/smileys/Confused.gif


No lift pump pre oem needed ...


Mac

Thanks Mack


Geno

Just a thought or question.


Is there really a concern with over-pressurizing the FICM with fuel pressure at 15 PSI. I have not seen the FICM apart, but I thought this was just a heat-sink, (maybe aluminum, maybe finned), for cooling the electronics within the FICM. I realize everything has pressure limits, but I would have thought that this heat-sink, being made of metal, would have pressure limits a lot higher.

My concerns about fuel pressure are strictly in regards to overworking the GM factory pressure regulator. I would think you would not want to provide so much fuel as to overcome bypass abillitys. There has to be a limit the factory regulator can effectively deal with. If you pass this point you run the risk of damaging the regulator itself of over feeding the common rail. There has to be a point where you change the engine operating parameters or damage factory parts. This might be a very high number such as 25PSI?


How does a GM tech. test if there is adequate fuel supply?

GM states to look for a vacum at the test port. If it's to high replace fuel filter and check again. If there are still problems check lines and fuel sender pickup, until problem resolved. The GM factory pressure regulator is made by Bosch and it's the same one that Bosch sells to Dodge. The Fuel pressure sendor is also the same one. So by following the Dodge guidelines I believe were in a safe operating range. Raiseing pressure above 15 psi and your on your own.

srode,


Pour some diesel into a clear container and look at it. All those tiny bubbles represent air - that you can clearly see. Place it into a clear container under vacuum (as in the fuel system but higher), and you will see it release entrained air and vaporize - like it is boiling. Increase the temperature, and it will do so at a lower vacuum.


Now roll under the truck and release one of the quick disconnect fittings that GM (and all others) is so fond of. You'll see an O-ring that seats against a ridge. It works great on a pressurized system, sucks air when placed under a vacuum.


The stock system works OK under most conditions and most people, but it's far from optimized, and something like the FASS addresses these issues. One could also install their own lift pump and filter and essentially do the same.Edited by: socaldmax

Okay let me get this straight. If I want to add a Nicktane do I have to add a lift pump? http://www.dieselplace.com/forum/smileys/Confused.gifhttp://www.dieselplace.com/forum/smileys/Confused.gif


No lift pump pre oem needed ...


Mac





Thanks Machttp://www.dieselplace.com/forum/smileys/Approve.gif