fuel press for modified engine

[Don Tanklage]

ps - have already taken it to 3k several times after installing the new lift pump and everything seemed fine



but when i got home and let it idle it did stumble intermittantly



however, i noticed only a decrease in rpm, no reving up stuff, so i think it is a problem with the lines



i hope

 

[Greenleaf]

Take it apart. At least pull the hydraulic head and look at the plunger and the rollers. If they are bright and shine/polished, your in no need of a rebuild. I'd hate to send a pump off to a shop and simply take their word for it that the head and cam plate/rollers were toast.



It may only need a set of seals and return springs. I just gave my 1990 a "tune-up" with new seals and replaced all the internal springs/throttle shaft/bushing. (pump was leaking fuel)Then installed new injectors. This was at 319,000 miles. The internals of said pump glowed like new.



GL

 

[Don Tanklage]

how do i do it GL



you got a ph number?



lol



yea, with all my questions i kinda doubt you want to pm me that number



all for diving in but i have no manual and no exp with these things



does the pump have to be removed to insp the mentioned items?



thanks



don

 

[Greenleaf]

The VE doesn't like over 15-16 psi. The seals blow much over that. You get more fuel to the injectors with 15 psi than you do with 5 psi.

Pete, and guys... ... ...



The internal (case pressure) is about 120 psi at OEM settings. However, the shaft lip seal IS under supply pressure, so it needs special care. A lip seal is not good for high pressure. O rings are used for that.



One point here, the vane pump has a passage to the shaft lip seal, but I don't know if fuel under case pressure is fed to that port. I guess it couldn't becasue at 120 psi, it would blow fuel into your engine. I need to break out the schematics.



I mentioned 120 psi "OEM" because it is adjustable and *IS* adjusted to produce more HP.



I was told at PDR that my information is "Proprietary" and "not for publication" If you want to know about internal pump pressure effecting HP, call them and ask. They could tell you or not tell you.

 

[Greenleaf]

Oh..... there is a web site with the manual published. IT's the VW site. The manual be for a four cylinder VE. WE, just add a few more DV's



Yes, pump is pulled. Pump is pulled anyhow to send it out... ... .....

 

[glhs]

Fuel pressure will lead to an increase in timing. KTA runs a rising rate pressure regulator that makes up to 50 psi to the supply side if I recall correctly. He has made a retainer to keep the front seal from popping out.

 

[Don Tanklage]

it sure seemed like mine ran better w more pressure



guess that is why

 

[dpuckett]

cerberusiam, you are right to a point. I thought the pump compounded the inlet pressure, exponentially of course, not lineally. It is more noticeable at the lower end of the spectrum. My truck ran better with a new LP than it did on the trip home from Houston.



Lots of ag and construction VE pumped engines have no lift pump. But it is like mentioned before- at 15hp per cylinder, it isnt that big of an issue.



DP

 

[bgilbert]

I run the same setup as KTA, Aeromotive A1000 and regulator. I've been running 12psi at idle, then at max boost of 60psi, my VE sees up to 50psi of fuel pressure- about max of what the A1000 will produce. So far so good, with no retainer. I'm guessing when the VE is being worked and needs the fuel, the big pressure isn't popping out the front seal.

 

[Don Tanklage]

what reg do you run with that set up?

 

[bgilbert]

what reg do you run with that set up?

This one:

Aeromotive A1000 Carbureted Bypass Fuel Pressure Regulators: AEI-13204 - summitracing.com

 

[Don Tanklage]

thanks



do you really think that pump is only good for 50 psi?



pretty sure if you deadhead one of those it will destroy a 200 psi gauge



does your motor really use that much volume?



(enough to drop it to 50)

 

[Don Tanklage]

ps - who did your 14mm pump?

 

[bgilbert]

thanks



do you really think that pump is only good for 50 psi?



pretty sure if you deadhead one of those it will destroy a 200 psi gauge



does your motor really use that much volume?



(enough to drop it to 50)

The only reason I say 50psi was a buddy of mine runs one with no regulator into his p-pump and said his fuel pressure was 50psi. He also has it pulling from the top of his tank instead of pushing/gravity fed from the bottom of the tank. This could have something to do with it. But according to Summits site, it says 45psi at 13. 5V. But also mentions 90psi max. Aeromotive A1000 Fuel Pumps: AEI-11101 - summitracing.com



KTA built my 14mm pump. GL did my 205 12mm pump on the other truck, which might flow as much fuel as the lowly 103 nonIC'd 14mm pump, who knows.



On edit: my fuel pressure gauge only goes to 30psi.

 

[Greenleaf]

The early P-Pump lift pump made by AC is used by some. It is easy to modify. It has two spings and one can be removed to lower the pressure a bit, to say around 22psi



I have yet to install mine.

 

[Don Tanklage]

does that pump flo more volume than the piston pump?



guess it would being designed for a p-pump appl



sounds like the piston pump is good for at least 450 rwh



i would think one of those (piston pump) with good lines and a large remote fliter would be a trouble free - long lasting - make lotsa smoke - great option



don

 

[Greenleaf]

I would suppose it flows more fuel. It was on a 1996 Cummins B and ran about 30-35 psi. It is a piston pump. With one spring removed, it should be in the low 20's. I don't know if it flows more then our first gen piston pump.



The new pump (for a P7100) is made by Carter and has only one spring. They too operate at 30 psi + however, the P-Pump has a pressure regulator as opposed to our orfice fitting.

 

[Don Tanklage]

i didnt think the first gens came with a piston pump?



and what do you mean by "orfice fitting"?



at the inlet or on the return? (just curious)



don



ps - plz answer my ques in the pm, thnx

 

[Greenleaf]

i didnt think the first gens came with a piston pump?



and what do you mean by "orfice fitting"?



at the inlet or on the return? (just curious)



don



ps - plz answer my ques in the pm, thnx

The piston lift pump would have to be installed by *YOU* There are many different piston lift pumps. All have an application. The orfice is the restriction in the return line. It be the fitting at the top of the pump where the return line connects to said pump.

 

[Don Tanklage]

thank you



don