Engine/Transmission (1998.5 - 2002) Engine Stumbles on highway

[MattChilds]

I have a stock 2001 2500 with the cummins motor. When I am going down the highway and back off the gas then get back into it the motor stumbles or misses for a couple of seconds and then picks up and runs fine. The problem probably happens more when I am towing my 3500# trailer than when I am running empty. I would say it happens once or twice in every 100 or so miles I drive.



I have changed the fuel filter and tried to only get fuel from busy truckstops.

 

[Turbo Tim 1]

Any performance modifications done to the truck? How about your fuel pressure? Have you checked it? A big problem with these trucks is the lift pump that feeds fuel to the injection pump. The LP's go bad and the truck will still run most of the time. Sometimes you won't notice any trouble, other times the truck will barely run or get terrible mileage.

 

[Hale on wheels]

Sounds like a lift pump going south to me. Mine had the same symptoms, and it didn't last long after those symptoms began, so be careful. Get it checked before it takes out your injector pump.

 

[MattChilds]

I have not done anything to the truck except put shocks on it.



Is there an easy way to check fuel pressure?



How hard is it to replace the lift pump?

 

[Hale on wheels]

There is a Schrader valve on the inlet of the injector pump, if you have a pressure gauge you can hook up to it.