Engine/Transmission (1998.5 - 2002) Lift Pump Again???

[DLausche]

This morning fuel pressure gauge was jumping wildly between 5 and 9 psi at idle, 3 to 7 at moderate throttle and 0 at WOT. LP was replaced under warranty ~3 months ago and before today has always had 14 psi idle, 10-11 WOT. Was about +10* outside this am. Engine ran fine - nothing to indicate something might be wrong. About 25 minutes into the commute to work, the FP reading returned to pretty much normal. 14 at idle, 8-9 WOT. Gauges were installed about 2 months ago and haven't had any problems (yet). First thought wouldn't be the gauge because of how the reading was jumping wildly up/down at random and in-between wide fluctuations the typical pulsing from the LP or VP44 was noticeable and a bit more pronounced than before. But then again, the gauge is new too so it could be faulty somehow. Other thought was that the FP isolator or line to gauge might be frozen. Wouldn't think this could be since I used 60/40 mix of new antifreeze/water and it wasn't too awfully cold out (+10*F). Fuel filter replaced about 8K ago and I always fuel up (including last time) at a larger fuel stop that is frequented quite often by truckers so I would think (assume) that the fuel I have is probably ok. Tank is currently at 3/8.



LP going out again, and so soon? Last LP was replaced because it was leaking. Thoughts much appreciated.



-Deon

 

[dresslered]

Interesting. Mine is doing the same thing. My first lift pump took 10,000 miles to slowly die. This one is somewhat more drastic like you are describing. Some days it works perfectly, other days it is all over the place (1-6 psi under light throttle) until it has run for a while. It almost appears that there is a sticking vane or something. I have a new one on my passenger seat to install.

 

[pgleavitt]

I have/had 12,000 miles on my last one(third one)and it always showed 15psi at idle and 9 psi at WOT. The problem I have is that it leaks. I just solved my problem with a FASS system. I will keep my spare lift pump to help out anyone I may see stuck on the side of the freeway.

 

[dresslered]

Look forward to watching you guys with the FASS system. Nobody has been able to offer me any evidence that the pumps used on these are any better, however. One thing for sure, mounting it back by the tank will definitely improve the situation. I might just do this with the OEM pump.

 

[Fireman Dave]

Deon,



I had a similar experience when my replacement pump was only about 500 miles old. That was 12,000 miles ago (about a year), and I see good steady pressure numbers since then. I don't know why the gauge acted the way it did then - maybe it had something to do with getting itself burped out after the pump change? I don't know. It did that only for a week or so, as I remember. It never got low enough to be able to get the dealer's attention, so I just watched it. It's been fine ever since. I have a mechanical gauge, by the way, so I don't think it was the gauge itself. The pump seems to be just fine, though.



Dave

 

[DLausche]

Thanks for the feedback guys/gals. Seemed fine on way home from work other than the FP at WOT seems to be a bit lower than before (8 now vs 11 b4 today). Will keep an eye on it and post more if it starts acting up again.



-Deon

 

[Gary - K7GLD]

Check to make sure the power plug into the LP is making proper contact. We just returned from a 3 month 8000 mile RV trip, and my original LP seemed to fail the last day before making it home. Yesterday, here back at home, I installed the spare I had for just such an occasion ( I have a pusher pump installed and it brought us on home with no problem!).



The replacement pump brought fuel pressure back to normal, but checking the removed original LP for electrical and mechanical operation shows NO problem whatsover - so my deduction at this point is that the contact at the plug was the culprit, and not the pump itself, and will watch to see what surfaces with the replacement LP.



I had checked for proper fuel PSI function by substituting an outboard mechanical meter, and also also for proper volage going down to the LP - but stupidly failed to actually check the plug connection itself - live and learn...

 

[CEkstam]

Lift Pump Life

I suspect that a mechanical failure in the existing transfer pump leads to increased motor loads that then leads to electrical overload and failure. Allthewhile over-stressing and damaging the fuel injection pump.



Fuel system components and peak engine performance depend on the fuel supply system for complete filtration and removal of contaminants from the fuel and proper pressure flow to the engine/ lift pump. The system should also have a means to monitor the system to guarantee performance. Entrained air, which can exceed 10% by volume and fuel vapor created by cavitation which is caused by insufficient pressure flow to the pump have not been recognized and fully understood fuel system issues until now.



The new Fuel Preporator Model FP-135A is smaller and quite suitable for pickups. The treated fuel supplied by the FUEL PREPORATOR system will considerably extend the life of YOUR FUEL INJECTOR PUMP and INJECTORS.



My suggestion would be to conduct a thorough investigation. We stand behind our product and offer a 60 day 100% money back satisfaction guarantee. Please feel free to contact us to discuss how the Fuel Preporator will not only assist your engine in reaching its maximum performance but also extend the operating life of several of its components (and save you a bunch of money!)





Thanks,



Charles L. Ekstam







YOUR FUEL INJECTOR PUMP and INJECTORS. YOUR FUEL INJECTOR PUMP and INJECTORS.

 

[MrFixit]

Mine leaked too

I did not know these pumps leaked, just that they failed pressures. I found mine leaking yesterday and dropped it by the dealer. They changed the pump and now my numbers are lower than my original pump. Old pump. . 15/13/8 new pump 12. 5/10/6. Don't like these numbers. I will have to check connection and ground too. 25K(2. 5 years) on my 1st pump.