Engine/Transmission (1998.5 - 2002) replacing stock lift pump... with a twist

[Stock Cummins]

About 3 years ago I purchased an 02 Dodge 2500 with a 5. 9 24 valve Cummins

The truck has about 460,000 km and as far as I know it's all stock.

The truck puts on only about 25,000 km per year... hauls my fifth wheel and a few other manly chores



Last fall it started "bucking" when I pressed the throttle pedal all the way down.

I didn't investigate as it was just before parking it for the winter, so I added a ton of fuel conditioner and left it.



This spring it's doing the same... It bucks when I hammer the throttle.

It starts and runs amazing.

I have been pulling my fifth wheel with it and can maintain a good speed, I can climb hills and can pass, so long as I don't punch it.



I want to replace the lift pump on the block... I'm guessing at this point it's the oem, which I think is amazing... 460,000 km on the oem lift??



Anyway, when I went to start investigating changing the OEM pump on the block, I noticed a pump along the frame... Just a little universal inline pump.

Some Cummins friends of mine think that the truck may have been modded at some point and it needed the extra fuel.



My question is, should I replace the OEM pump on the block with a Universal or Delphi or BD? AND... should I eliminate the pump on the frame or replace the pump on the frame or leave it as is??

 

[DAN V]

leave frame pump alone

your frame pump is a pusher pump. I would leave it alone. As for replacing the stock lift pump on the block I would go with Blue Chip Diesel and get their pure flow FRRP. This will put out a constant 15 psi. I plan to do this to my truck in the future. The bucking you mention, I had the same thing happen to me on an older 2nd gen and it was the VP-44. I had it replaced and truck ran great after that.

 

[DAN V]

Gauges

Do you have any gauges? I would recommend at least a FP gauge to monitor your FP off the VP-44.

 

[Stock Cummins]

No gauge yet... working on that too.
I'm curious though... if the "pusher" pump is worn out or malfunctioning, is it still useful?
I understand the Logic of having a "pusher" pump, but if it's restricting, not working, malfunctioning - it would be holding fuel back from the lift pump??

 

[DAN V]

No gauge yet... working on that too.

I'm curious though... if the "pusher" pump is worn out or malfunctioning, is it still useful?

I understand the Logic of having a "pusher" pump, but if it's restricting, not working, malfunctioning - it would be holding fuel back from the lift pump??

That could be the case also. You might pull the pusher and see if it is clogged.

 

[Stock Cummins]

any preference on a replacement lift pump?
there is SO much advertising about one product being better than another
the parts tech at my local cummins store said to stick with the oem lift pump... but I'm nervous about that too
I was looking at a little Delphi on ebay http://www.ebay.com/itm/161013375744?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
and a little walbro http://www.ebay.com/itm/220523160008?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Any opinion??

 

[klcammie]

your frame pump is a pusher pump. I would leave it alone. As for replacing the stock lift pump on the block I would go with Blue Chip Diesel and get their pure flow FRRP. This will put out a constant 15 psi. I plan to do this to my truck in the future. The bucking you mention, I had the same thing happen to me on an older 2nd gen and it was the VP-44. I had it replaced and truck ran great after that.

I agree. I put one of these on my 01 2 months ago and so far have been very happy with it. The one I got is adjustable, but would not go under 24psi with my extra pusher ump. I called and got great service, they had me cut one coil off the spring, now 19 psi at idle, 17 at freeway speed 14- 15 at wot.

 

[JR]

First things first, before replacing anything I would put a fuel pressure gauge after the fuel filter to see what your getting. The bucking could be from low lift pump pressure starving the vp under heavy load or wot. If thats the case your burning your vp up with every passing mile...

Or maybe you have good lift pump pressure and have another totally unrelated issue, which is why I would install a guage before doing anything else.

 

[Frosty4455]

Hello, new to the site and forum. I have a "01" 2500 5. 9 I replaced my lift pump 1. 5 yrs ago. At first I was going to go the cheap route & do the OEM but after talking to the Mechs. at work (diesel) they all said why replace with something that already has given problems with a new OEM especially since the OEM has inherent problems. They recommended a FASS pump, the output meets and exceeds what the injector pump needs. It cost about $300 for the pump and installed myself - very happy with it and is warrantied for 5yrs I believe. Just my 2 cents worth.

 

[DClark]

Two points, Diesel4life is correct. Do that first. Second forget the OEM lift pump. That system was so problematic that even Dodge admitted it and replaced it with an in tank LP which is still used on current trucks. You can get that one or get an aftermarket pump mounted on the frame rail.
DClark