Engine/Transmission (1998.5 - 2002) Another FASS question

[cumminscanuck]

In the last couple of days I've noticed that my fuel pressure behaviour has changed. When I turn on the ignition the FASS pump runs briefly but the pressure only gets, very slowly, to 5 psi. If I bump the starter the pump runs for about 25 seconds and the pressure reaches, slowly and in lurches, 15 psi. I can now pull the pressure down to around 5 psi with the throttle which I could never do before. The pressure sensor is directly before the VP44 and I know that the problem is not in the gauge circuit. Also, the fuel filter was only changed about 1k kms. ago. Any ideas before I rip the pump off and send it back to FASS?

 

[SMcGrady]

What kind of gauge set-up do you have? I would be sure that all the components of the F/P gauge, diaphram, hoses are working/not leaking, before I would blame the lift pump. You might try a test gauge to verify if what you are seeing is really the case.

 

[cumminscanuck]

What kind of gauge set-up do you have? I would be sure that all the components of the F/P gauge, diaphram, hoses are working/not leaking, before I would blame the lift pump. You might try a test gauge to verify if what you are seeing is really the case.

The gauge is an Isspro mechanical operating through an isolator. It has been thoroughly tested and every component has been checked with another pump. The gauge is not part of the problem.

 

[cumminscanuck]

I decided to remove the pump and fit a spare that a friend loaned me. While trying to disconnect the fuel feed line from my FASS at the pump end the whole pipe fell on the floor. The quick release fitting was stuck in the unlock position so the feed pipe was just held on the tank by friction causing the FASS to suck some air with the fuel as the fitting worked loose. Some WD40 and a new length of pipe cured the problem. I'm glad it did not give up on the side of the highway

 

[SMcGrady]

I decided to remove the pump and fit a spare that a friend loaned me. While trying to disconnect the fuel feed line from my FASS at the pump end the whole pipe fell on the floor. The quick release fitting was stuck in the unlock position so the feed pipe was just held on the tank by friction causing the FASS to suck some air with the fuel as the fitting worked loose. Some WD40 and a new length of pipe cured the problem. I'm glad it did not give up on the side of the highway

Nice!:-laf:-laf:-laf