Engine/Transmission (1994 - 1998) lift pump

[JIM S.]

this may be a dumb question... . but, can a "on its way out" lift pump cause a loss in fuel mileage?

Jim

 

[Joe G.]

I don't think so. It would get hard to start and maybe not have the power it should have. As long as the injection pump gets fuel it should not affect your milage. You need a fuel pressure gauge.

 

[JIM S.]

Logic. . (mine anyway) told me just that... . the lift pump shouldnt have much effect on milage... but I thought I would ask cause I dont know. I am pretty sure my lower MPG is coming from the short trips,cold weather and my tourqe converter is getting looser .

Jim

 

[Joe G.]

Winter fuel formulation doesn't help either.

 

[illflem]

For sure a plugged fuel filter will lower your mileage, not sure why. Seems like a failing pump could have the same effect. Short trips without ever fully warming up probably cuts into your mpgs more than any other factor. Like Joe said, you need a gauge. A simple in cab non-lit mechanical gauge setup can be put together for under $25.

 

[chrleb1]

Low fuel pressure can cut into your fuel mileage some. But there are a couple ways to have this problem. Lift pump, Overflow Valve, and filter. Check out the easy ones before automatically going to the lift pump.