Engine/Transmission (1994 - 1998) Lift pump

[firemanmarc]

My lift pump is leaking fuel around the primer button when running. I assume this means my pump is bad. . I have a lift pump from an industrial engine that is new. My Cummins shop said the pressure my be too high and blow front seal of injection pump. My question is what kind of pressure should I be looking for, I can't believe an industrial engine would run that much more pressure. . And has anyone elimated the heater,filter from there pump, it is pretty clear that the heater wasn't working anyway. Thanks, marc

 

[Joe G.]

You probably have a bad O-ring around the push button. It's about 50 cents at NAPA. You should have at least 18 PSI at ldle. Anything up to 40 PSI is ok on the road. 2000 RPM with no load should be at least 22 PSI.



The heater is really easy to remove. Use a 17mm socket to remove the pre-filter. An 8mm allen wrench to remove the heater. The pre-filter will bolt right up without the fuel heater in there. Look at pictures of the fuel heater in my Reader's Rigs gallery.

 

[firemanmarc]

Thank you, also I read that you can rebuild the pump?? The pushrod doesn't act like it is pushing against pressure, it does pump fuel, it just seems wierd. I plan on pulling apart here in a few minutes, I suppose if I fix it great, if I don't, then I get a new one!!!. . Thanks again, Marc

 

[Joe G.]

I don't know of a parts source for the lift pump. If anyone finds one I would like to know. What you can do by taking it apart is to inspect the parts. If the springs and check valves are not broken, the pump is ok. Even with weak springs it will still pump but fuel pressure will be low. The springs are what moves the fuel. The push rod just compresses the springs. Look for a scarred up piston. Make sure that the check valves are all installed so fuel will flow from the input to the output when you put it back together. It's really a simple gadget.