FI fuel press ?

[TBK1]

77, is the fuel pressure supposed to bleed down over night. have gauge installed to monitor, this is a new project so not a bigf deal right now, but have noticed the oil is real thin, prob gas in it, and the plugs dont look terribly bad?? thinking maybe one of the injectors is leaking?

[sblake01]

It should hold the pressure over night. Theoretically, it should hold it indefinately as long as there are no leaks.

[veritech-z]

My 77 doesn't hold pressure either, but I've got a fuel cell and an aftermarket rail, so I'm not so sure that whatever the mechanism is for keeping the pressure up with the pump turned off is working in the same way. I don't have the charcoal canister anymore, but I am still using a stock pump with the damper still in place. I always thought the damper acted as a sort of anti-drainback mechanism, but evidently that's not the case. When I turn off the pump, the fuel pressure gauge on my rail goes from 45 psi down to about 10, then if left long enough, to 0. I just put my fuel pump on a switch and let it run for a few seconds before I start the car.

[sblake01]

The check valve on the stock fuel pump is actually the anti drainback device. All the damper does is smooth out the fuel pulse.

[Darrel]

#1 check for fuel injector leaks, including the cold start injector.

#2 the check valve might need replaced that is in the electric fuel pump.

More than likely the problem is one or more of the injectors leaking.

[TBK1]

thats whatn i thought, something else to add to the list.

[TBK1]

Is there a way to test each injector for leaking while they are still installed?

[sblake01]

Not that I know of.

[TBK1]

of course not, oh well, just another project anyway.

[TomoHawk]

When I overhauled my injector rail (In February,) I still had loads of pressure on it after I put the car away in November. That's probably what's up with mine; I soaked it in evapOrust to clean up the outside, and some of it probably got inside. So at WOT, I don't get full fuel pressure.