Engine/Transmission (1998.5 - 2002) Lift Pump

[Brashear]

My lift pump has gone out. A local diesel mechanic wants to replace it with a Delphi unit for about $350 m&l. He also commented on that my injector pump was probably damaged when the lift pump went out, is this possible? I've reviewed a number of post and nobody has mentioned this before.

 

[rkressg]

First off, welcome to the TDR. You will find a plethora of information available to you here. If you have any questions, please ask.



Hopefully this information helps.



A replacement lift pump can be purchased from Dodge for around $220. They can be purchased from a Cummins dealer for as low as $120. They will come in the same Cummins box, but the Dodge one will have a MOPAR sticker on the side (over top of the Cummins sticker).



Changing a lift pump takes about 10min. It only requires a 18mm wrench (stubby will make it easier), a 13 and a 10mm socket and ratchet.



You only have to un-bolt the two fuel lines (two banjo bolts), be careful when doing this, because there are washers on these bolts and you do not want to drop them. There is a wire harness connected on the right side, remove this, and remove the three bolts holding the lift pump to the bracket. You will also need to remove the bolt holding the fuel line to the pump bracket.



It is an extremely easy change.



Yes, it is possible that you have damaged the VP44 (injecton pump) by not having sufficent fuel volume flowing to the pump. The pump is fuel lubricated and fuel cooled. Approximately 70% (if not more) of the fuel that is pumped to the VP44 is returned to the tank.



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If you are anywhere near Pittsburgh, I would be more than happy to show you how to change a Lift Pump.

-Rich

 

[jerrethomas]

when my stock liftpump went bad i replaced it with a delphi pump(still made by carter). that pump lasted a little under 6 months. Had low fuel pressure again so i replaced it with another delphi, i've had this one in for about 3 or 4 months and no problems so far. i also moved mine back to the tank now.

 

[ThrottleJockey]

Brashear,



This lift pump thing will drive you to drink if you let it... .

 

[DJW]

I have a 2001 CTD no mods, 5300 miles, what pressures should I read on a gauge located off the top of an Geno's metal filter housing cover, at Idle to Wide Open? Scrum Down

 

[RJPotts]

Your VP is happy with around 15 psi post filter all the time at idle, I would say 10psi at WOT is the safe limit. 8psi is acceptable but not for long periods of time.

My lift pump went out long before I purchased my truck (still under warranty thank the Lord) and it took around 3000 mi. with a dead lift pump to start showing any signs that the VP was sick. So, yes, a dead lift pump will do some damage to the VP no matter how long its been at low pressure, it just depends on how much and how long it has to fail completely.

When you get a dead pedal, stumbling, missing, white smoke at N. O. T and poor fuel economy and performance you'll know your VP is laying in bed with a thermometer in its mouth calling all of its relatives and a lawyer to write out its last will and testament.

-R. J.

 

[fkovalski]

Your VP is happy with around 15 psi post filter all the time at idle, I would say 10psi at WOT is the safe limit. 8psi is acceptable but not for long periods of time.

I have heard that pressure under WOT down to under 5psi can be acceptable and normal. is this true?



Also- I heard from my dealer that they test lift pumps by volume as opposed to pressure. Which method is more accuate.



I am very much interested in this thread as I will be putting on a gauge soon on mine and want to understand the numbers better. Thanks for any input. -frank.

 

[RJPotts]

Volume is more important than pressure for the VP, definitely. As for which method is more accurate, I don't know if thats a fair comparison because you're measuring two different things. I've heard of 5psi at WOT, I've heard of people running it down to 0 psi at WOT. I'm not sure of the reprocussions of low FP for such a short period of time, I can't imagine its the best for the VP, but it can't really be bad. Its still getting fuel to lubricate and cool the internals just not as much as it may like.

I would guess that low FP is only truly harmful when it is sustained, like when the lift pump fails. Thats why we have FP gauges.

-R. J.

 

[amnewsom]

I just installed my FP gauge and I see about 13. 5 - 14 lbs at idle, 11 cruise and no less than 9. 5 pounds WOT fuel dump. I am installing a EZ this weekend and we will see what happens but the pump is solid and does not waiver in pressure so I am cautious but I am not going to rush out and buy a new LP, yet.



Good luck, I have but about 40,000 miles on my truck and just put a FP gauge on with multiple trips towing and not over long distances at sustained speeds. So long and short, 13. 5 idle doesnt bother me.



T

 

[ThrottleJockey]

amnewsome,



I think you should rush out and buy a new lift pump to keep in your truck. The thing ain't DC's crowning point of engineering achievement.