Engine/Transmission (1998.5 - 2002) Lift Pump looses pressure at 1900 RPM

[draymorris]

My fuel pressure sending unit is on the banjo coupling on the filter - on the line to the injector pump. I have 15 to 16 psi all the time when I am idling and upto about 1900 rpms depending on my accelration rate. In 3rd gear and up, I lose pressure at approximately 1900 rpms - and I mean lose pressure! It almost instantly goes to zero until I let off some. Furthur more this doesn't happen when the outside temp is 50F or more. My questions are: Is this a symptom of a failing pump? If so, why normal pressure when fuel demand is low? I know the fuel gets "thicker" at cold temps, but 40F is not that cold ,is it? And fuel treatment doesn't solve the problem. Could this be a clogged internal pump filter - if my 02 has one? Could this be a restriction in my new banjo bolt that I installed to intall the sending unit? Where should I start to solve the problem? I have changed the filter many times. I run a Diablo Power Puck if it matters.

 

[Ron Bissett]

If the gauge is good you have a failed pump psi should never go below 8 psi your wot is showing 0 and that is a no no . I would get a second gauge mech or elect and check the mounted gauge. Ron in Louisville KY