Engine/Transmission (1998.5 - 2002) lift pump

[ctopp]

Based on the problems experienced with the factory lift pump on my 98. 5 I want to replace it to avoid any risk of damaging the fuel injection pump. Is the Cummins replacement pump the best way to go or is there a 3rd party supplier with a better pump? Any advice would be appreciated.

 

[KIseminger]

This is not from experience but going off of what others have said, get rid of your lift pump all together and go with an aftermarket pump. Get a fuel pressure gauge too; then if your lift pump does go bad, you will know. My 02's lift pump went out and the injection pump was trashed. That was at 36k. Thank god for warrentee. The pump alone is around $1500 I think.



-Kyle

 

[lizzyhermit]

not hypothetical amounts

injection pump = $2362. 00

core return = $800. 00

labor = $378. 68

towing = $38. 00



an injection pump is NOT a cheap experience. but ya know what?



I still love my truck !

 

[KIseminger]

Wow, that was more than I remember. No it is not a cheap thing. Then again I didn't have to pay a dime. It just took 4 trips to the dealer to get it resolved.



But I still love my truck too

 

[Sticks]

Man I see a lot of you guys that got hammered on this injection pump $$$. That is a $1500 part ($1000 average, and as low as $750) on the expensive side, and a reworked performance pump is only $1900.



The OEM LP is a good pump, just in the wrong spot. Spend $70 and move it to the frame rail by the tank. I did mine and I idle at 16. 5 and have yet to pull it below 12. On the highway at 80mph holds at 14. 5psi.

 

[ctopp]

Thanks for the advice guys. I am out of warranty and not interested in buying a new injection pump. I have nearly 90K miles on the lift pump and probably ought to replace it. Anybody recommend a good aftermarket pump?

ctopp

 

[rweis]

My . 02 receipe for the fuel system



1. GAUGE the lp and VP

2. move the OEM lp to the frame so it can PUSH and not suck

3. replace the fuel lines with at least AN-6, I would do AN-8 if I did it again

4. get rid of the banjos with full flow fittings the fewer bends the better

5. water / particle filter before the lp for best possible input to lp

6. bypass after the lp to keep the check valve ball seated



The only thing I would add to Sticks is that check valve in the OEM lp is what normally goes down when the lp "dies". My point is to keep the check valve from operating in the first place with a bypass regulator.



Mine feeds the VP a steady 12psi at idle to 10psi under WOT. At those psi the check valve in the OEM lp should never come off the seat and therefore never be the point of failure.



No one thing is the silver bullet for the fuel system



Bob Weis

 

[prgilbert]

I'm new to the Cummins lift pump saga and am concerned about the failure rate plus the potential damage to the VP. I would like to move the pump to the frame rail (seems to be a reasonable solution) does anyone have details with pictures of this setup?

Thanks

 

[JPLB22]

prgilbert...



Here is good one for you.



https://www.turbodieselregister.com...id=77891&highlight=lift+and+pump+and+relocate





P. S. The second post down is the simple instructions. The link in the first post is a little more involved.



Jeff

 

[prgilbert]

Thanks, I'll be doing some reading and preplanning.

 

[Sticks]

The link is an excellent write up. Do a search on "Relocate*+ Lift +Pump" There are several different methods to do this using a variety of different fittings and lines.

 

[tmacc]

At 124K, here is my experience w/ LPs. At 9K the dealer replaced LP due recall of my particular LP. Installed a FP gauge not long after that. I probably got about 50K before the PSI started to slowly drop on that LP. I then installed a Carter 4601 back by the tank and it was great for about 30K and then when it dropped to about 12PSI, I installed another 4601, but it only produced 12PSI from the get-go. I ran it anyway for about 15 K and then it dropped to 5PSI so I re-installed the "old" 4601 and ran it for another 15K till it dropped to 3PSI:--) Yikes!!! So I then went to the local Cummins shop and for $120 bought a Cummins LP and it produces 16PSI at idle and sits at 14. 5PSI at 70-75 MPH. My truck is only lightly BOMBed at 350/824, so IMO a stock pump would be fine for a mildly BOMBed truck. You will need (3) weber fittings to run new lines from the rear mounted pump to the fuel filter though. You can get them from JEGs or Summit. I don't have the part number handy, but they are a 1mm x 12mm male to 3/8 tapered male fitting. HTH

 

[ctopp]

Thanks to all who have posted. I have learned alot about the lift pump issues.

I have an in-bed American auxillary fuel tank/tool box combo. The fuel supply and return lines are piped to a 6-port selector valve, along with the supply and return lines for the OEM tank. The selector valve is on the suction side of the lift pump, thereby adding more pressure drop (suction head) to the lift pump.

Moving the l/p down to the frame should help, but does anyone know what the pressure drop through the selector valve is?

I read another thread where they added a transfer pump and just move fuel from the OEM to the auxillary tank and do not have a selector valve. That would be less convenient.

ctopp

 

[BKilbury]

Another item that I installed are banjo fittings with larger holes in them. At $40 for the 5 of them it could be cheap insurance, possibly flow a little easier

 

[tmacc]

The fitting that I mentioned above if you want to use a Cummins or OEM pump back by the tanks is a Earls Mfg. #991944. This will bolt directly to the lift pump and fuel filter housing. The other end is a AN-6 male not a 3/8"NPT as I mentioned before. I used -6 PushLok female fittings and 3/8 PushLok fuel line to hook everything up. Very easy. I installed a ball valve between the tank and the lift pump so I can cut off the fuel to the pump if neeeded. It sure has come in handy w/ having to change the pump out three times in the last 1. 5 years or so. Hopefully the Cummins pump will last for a while. HTH