Lift Pump Number

[BMC96]

I did a search for the new lift pump number and came up with 2 numbers. 3938435 - 3990105

Can anyone tell me which is the right one. My truck is a 99, so do I need the harness to hook it up with. Harness # 4025182. I was just going to call cummins tomorrow and order over the phone and wanted to know the right #'s. Alot less hassle.

Also going to order the red valve cover # 3943668.

Going to put injectors, banjo fittings, lift pump, and valve cover on this week some time and wanted to do it all at the same time. Thanks Barry

 

[pwr2tow]

Cummins #'s

Lift pump # 3990105

harness # 4025182

Banjo seals #3935171

you probalbly will not need the banjo seals, I have reused mine 4 times including the original install from factory.

Ron

 

[BMC96]

Thanks Ron I see you changed the IAT sensor and it made a difference. What problem did you have to change it? and the part number if you have it.

Barry

 

[pwr2tow]

The IAT is simple to change out, I do not remember the size socket but it is located on drivers side between fuel filter and firewall behind MAP sensor (closer to firewall). If memory serves me, There are two sensors with connector plugs back there, it is the one closest to the firewall.

IAT # 05014197AA This is a Mopar number.

Ron

 

[BMC96]

Ron thanks for the reply, but I didn't ask my question very clearly. What problems were you having with your truck to change out the IAT sensor? Barry

 

[pwr2tow]

Poor fuel mileage and alot of hassles getting my dealer to listen and I thought whats another $22. 00 if it helps. By the way the dealer didn't help but the TDR has paid for itself a hundred times over.

very small price to pay.

Ron

 

[BMC96]

Thanks for the reply. I have been only getting 13 to 15mpg (country roads) My 96 did better, but it was a 5 speed. Might be worth a try. Barry

 

[CoastyAV8R]

BMC,

Why are you replacing the lift pump? Low pressure or preventive maintenance? I'm trying to see at what pressure people are replacing their lift pumps at. I currently get 13 psi at idle and about 9-10 WOT.



Pat

2001 ETH

 

[pwr2tow]

Those are good numbers and i wouldn't worry about pressures until They fall below 8psi at 2700 RPM's under WOT at full load.

Ron

 

[BMC96]

CoastyAV8R, preventive maintenance mostly,(have on shelf) but wont change unless needed. Going to change injectors and banjo's. Just trying to cover anything that might go wrong down the road.

Barry

 

[Whitmore]

Ronsram, thanks for the cummins lift pump numbers , I am calling today and getting a new one, My lift pump is shot at 22k and the stealer says drive it down here (40 miles) and we will test it and then order parts , NOT , I told them I will fix it myself the right way. I plan on doing the cummins lift pump and then re-evaluating my options for a pusher Thanks again and yes the TDR and its members are far far better than my warrenty will ever be... ... ... ... ..... CHEERS FELLAS ... ... . Kevin

 

[pwr2tow]

Whitmore,

Your welcome.

You might not need the wire harness for the 2001 model truck. I'am not sure on the 2001 models if you can replace the pump from the engine bay. Take a look and see if you can remove your filter canister and bracket and reach the pump from up top, I think it is easier than removeing the starter to get at the pump. It is about a hour job the first time and after you do it a few time can probably be done in about 30-40 minutes. I'am too peticulair about things so it takes me longer than most.

Ron

 

[Whitmore]

Up-date- I drove to town this morning (in the car) and picked up a new lift pump from cummins, yes that is the correct #3990105 and it costs $142. 66 , Ron you are right the 2001 does'nt need the wiring harness. Anywho the install took place all from the top, not to bad, 45 minutes, and yes I took the fuel filter bracket loose and let it fall forward out of the way, this is manditory unless you are a contorshunist(sp) . Results- 15 psi at idle and 13-14 at 75mph on flat ground 12 at small hills and I can pull it down to 3 psi at WOT but it recovers to 6 psi before I reach 100 mph . I will be very curious to see what it will do with a load and going up hill at WOT, this number will tell me weather or not to install a pusher to the lift ,I will wait and see on that one.



I took both pumps apart while on the bench and compared them and found no difference in fact the old pump looked fine , the vains looked good with no wear and the screen was clean so the only thing that I can figure is its in the speed of the electric motor??? bit it looks identical to the cummins pump.



The CUMMINS guy told me that there is an internal pump inside the VP-44 that takes the psi up to 300 , I got to thinking on the way home and I wonder if the by-pass is before of after the internal pump? I would think it is before the internal pump because we dont want 300 psi fuel returning to the tank any who I just wanted to share my fun with all so we may as a group come up with the ultimate set up for the dreaded lift pump... ... ... ..... Kevin

 

[pwr2tow]

I was surprised to see you could pull the psi down to 3 on a WOT run with EZ and 275's. It seems these pumps are weak from the get go.

I was going to install my pump back by the fuel tank and run rubber fuel line up to fuel filter but I needed the truck running right away and didn't have time to mess with makeing a bracket and shield to mount to the frame. When it warms up (above -10F) I am going to do these things and have them ready for next time.

Ron

 

[Whitmore]

Ron, that is exactly my take on the deal, I plan on moving the pump as far back as I can, we will see what that will do???Kevin