My uncle has a 98 2500 4x4 24valve cummins he bought used with about 100,000 miles on it not too long ago. It has probably about 130,000 miles, and has original lift pump, and has been a farm truck all its life. Its probably never had anything changed but the oil, and oil filter. When he steps down on it hard, it revs fine, and has good power until it gets so high in rpm's, then it starts missing, and blowing blue smoke like its starving for fuel. My uncle originally thought it was the fuel filter, but we havent changed it yet, so were not sure. Then i started thinking about how the lift pumps go bad a lot(especially this early of a model), and so i said something to him about it. He doesent have a pressure guage, and i just dont want his injector pump to die on him, and cost him a lot of $ when it could be fixed, and monitored very easily, and fairly cheap. Can you hear the LP run when you turn the key to the on position? Do you guys think this could be the problem? It shoots a nice puff of black smoke every time he starts it, and it runs good except for the missing/cutting out when you rev it very high. Any help is appreciated.


Eric

 

well mine went dead @ 120K but I can pretty much gaurantee that his pump is bad especially with that symptom also change the fuel filter but 99% chance that pump is dead, you can hear if the pump is running when you turn the key to the on position & it will run for about 3 sec's to prime, but just because you can hear it run does not mean it's pumping enough fuel, the pump is most likely dead, if it were me I would just change it, but if oyu have the gauge to check it do that.

DRecu!

PS also check the air filter also!

 

Do yourself a large favor and get that pressure checked. I never checked mine until the truck just went over 100k and it was about 5 idle and easily drawn down to zero and less that WOT.
There are several articles on here on how to change them out. I am working on LP number four and have got the changeout down to about 35 minutes including removal of the filter housing.

If you can't find the step by step, drop me an e-mail and I will send it to you.

joel.williams@rcn.com

 

Thanks for the help guys.

Eric

 

Change the fuel filter-then put on a gauge.

 

Well, if it was my truck, id change the fuel filter, then put on a fuel pressure gauge even if the fuel filter didnt fix it, and then if it showed low #'s or still didnt run right id change the LP. But, this truck is my uncles, so it will be hard for me to convince him to change it, or put on a pressure gauge. Thanks for all the help guys, ill try to get him to change it, or put on a pressure gauge if i can.

Eric

 

He should be easy to convince, just get a price on a new lift pump, a pressure gauge, and an injector pump. The injector pump is what he will need if he don't get the first two to see what is going on. If that don't convince him, we tried.

 

OK guys. Update. Now when you are just cruising along, the truck misses, and blows white smoke. It is apparenly getting worse. Where exactly is the lift pump? I am thinking about just buying a gauge myself, and putting on his truck. Can you just get one from like auto zone or somewhere, and just mount it under the hood. Im sure that wouldnt be the best place, but we could check it anyway . What all would i need, if i hooked up a pressure gauge? About what would it cost? What kind of adapter does it take to fit the fitting on the pump that gives the reading? Today, we listened for the lift pump when i turned the key on, but couldnt here it. Is it on the drivers side of the engine block? Thanks for all the help guys. We really need to get this fixed whatever it is.

Eric

 

Try going to Genosgarage.com and looking at the Westach fuel pressure guages. They are not expensive at all. They even include a fuel sending unit. (The guage is electric) The only thing that you supply is the wiring which is minimal, and a rubber grease gun hose to connect the sending unit to the top of your fuel filter housing. Like all the others said, your uncles lift pump is shot, REPLACE IT BEFORE THE INJECTOR PUMP GIVES UP. After replacing the lift pump, go to your local Napa store and have them order a pusher pump that installs inline between the tank and the lift pump. The part number is P4601HP and is made by Carter. It flows at about 16 psi and has a rate of 100 gallons/ hour. I have heard that after the installation of this, no more lift pump failures. I ordered mine yesterday, should have by Monday or Tuesday.

 

Thanks Cody. Ill check into genos garage, and see about it.

Eric

 

The following is for a 2004 model but it's probably not too much different as a guess.

The fuel transfer (lift) pump is self-priming: When
the key is first turned on (without cranking engine),
the pump operates for approximately 1 to 2 second
and then shuts off. The pump will also operate for up
to 25 seconds after the starter is quickly engaged,
and then disengaged without allowing the engine to
start.

REMOVAL:
(1) Drain fuel from fuel filter housing. Refer to
Fuel Filter/Water Separator - Removal. See Draining.
(2) Disconnect electrical connector (Fig. 23) from
fuel transfer pump.
(3) Disconnect fuel tank supply line from fuel
transfer pump extension line. This is done at disconnection
point at inside of left inner frame rail (Fig.
24). Refer to quick-connect fittings for procedures.
(4) Remove 4 pump mounting bolts (hex-allen),
and remove pump from fuel filter housing.
(5) Confirm that transfer pump o-ring is also
removed from fuel filter housing.

INSTALLATION:
(1) Install a new o-ring to fuel transfer pump.
(2) Lubricate o-ring and OD of transfer pump inlet
connector.
(3) Position fuel transfer pump onto fuel filter
housing. Do not use mounting bolts to draw
transfer pump to filter housing.
(4) Be sure pump is positioned flat to fuel filter
housing. Install mounting bolts and evenly tighten to
7 N·m (61 in. lbs.).
(5) Connect fuel line extension at fuel supply line.
(6) Connect electrical connector to pump.
(7) Prime System: Cycle key to actuate transfer
pump, or use DRB Scan Tool to actuate transfer
pump. Check for leaks.
(8) Operate engine and check for fuel leaks.

I have 2 more pictures to post that deal with the removal/installation process............

 

Lift pump picture from 2004 manual

 

Thanks a lot handymantim. That will definatley help us in trying to find out whats wrong, and replacing it if we have to. Thanks a lot.

Eric

 

Fuel Line Pic

 

Heres a link of a fuel pressure guage that you might want to look into.

http://www.protintnw.com/sa_dodge-fuel.htm