Complete Lift Pump Failure!

[DEZLPWR]

Well, I had a feeling that my lift pump was going bad ever since I changed the fuel filter 2 weeks ago and could not get the fuel system to prime. I took the truck in to Cummins NW tonight and they confirmed my suspicions: the lift pump is completely dead. 0 psi across the board, regardless of RPM!

The funny thing is that the truck has always ran perfect without a stumble. The only indication that I had of it even being possibly bad was that it would not prime when I did the fuel filter change.



I have no idea how long it has been bad. Dealer did the last fuel filter change 10,000 mi ago.



What I also thought was interesting was that the Cummins service tech said that I don't need to worry about damaging the injector pump by driving around with a bad lift pump because the injector pump is getting enough fuel via the vacuum that it creates. He said that is why it drives just fine without any noticible indications.



Is this B. S. or not? I have heard here on TDR to the contrary that a bad lift pump can lead to injector failure. Now I am paranoid about my injection pump!



Now I get to call Dodge tomorrow and see if it will be covered under the engine warranty since my 3yr/36000mi bumper-to-bumper has expired.



Sorry for the long post,



Steve

 

[Michael Hughes]

Steve,

My lift pump was bad also and didn't know till I changed the fuel filter. Based on what the Dodge dealer in Festus MO said, the lift pump is covered under the 100,000 mile warranty.



If not, get yourself one at the Cummins services center, it should be $139. It takes about 45 mintures to change.

 

[Ron Bissett]

Don't forget to order a fuel pressure gauge your choise but get one take the guess work out of lift pump work or not ,You should know before the dealer if its working or not. Ron in Louisville KY P. S when starting I watch the FP guage as I turn the Key to run position pointer moves to about ten psi then falls back to rest position (4psi ) as I turn key to start position and start eng guage pointer moves to ten to eleven psi ,so I know pump is working and it stays at this psi most of the time to shut down of eng.

 

[David_VT]

I primed from above...

Had the same problem with a weak lift pump...



I was able to prime from above...



see my ALPS thread

 

[Ramafid]

I think the lift pump is very important to the life of the injection pump. Why would they use a lift pump if it doesn't make any difference? Just cruising around more than likely won't stress the injection pump but add a big load and work the engine hard and I think you're going to have a problem. Changing my lift pump and adding a fuel pressure gauge was cheap insurance in my opinion.

 

[Bigsaint]

My neighbor is a Dodge tech. and he told me the same thing when my first Mallory died. I tried driving, for all of 2 1/10's of a mile, felt alot of resistance, i. e. , stumbling, low power, while attempting to accelerate. I ending up parking the truck for fear of doing more damage.



No doubt, the VP44 does suck (no pun intented). When the 4150 died, my FP reading was -11 psi's.



I would hazard a guess here that anyone that has had their lift pump tested and found zero psi's, but the truck still ran, even under throttle, not just idle, had a lift pump that was on it's way out but not entirely dead. I can tell you first hand, my truck would not drive normally with a dead Mallory. Perhaps the gerator pump added more of a restriction to the sucking VP44 when it died, rather than the Carter ?



Scott W.

 

[JEMOORE]

Just my opinion

If your truck had been running fine I don't think I would worry about the main injector pump being damaged. In my opinion if it got enough fuel to run OK it got enough to lube the V-44 pump. I have an old Case 580-CK backhoe (early 70's) that almost always has some water in the tank and also the filter housings when I drain them. I never change the fuel filters until I feel a loss of power I mean like its running out of fuel Needless to say the filters look pretty bad when I do change them. I've also ran it out of fuel many times. So far, after all these years, no injector pump problems. (knock on wood) I will never abuse my cummins in this way ( I hope) although I would be disappointed if it would not take it occasionally. We all bought these trucks because they are supposed to be tough. I don't expect we have to baby them!