Thanks Rusty, I sure hope that it is. This has been kicking my butt. It needed so much repaired but these last few gremlins have been hard for me to chase down. I’ve never taken a vehicle to a shop unless it was warranty work but I decided to take this one early on and was disappointed.

Its a shop we use for work and I thought they would be a reliable repair. They said it was the injection system and replaced that and a few vacuum lines. It improved slightly and got rid of the hard start but still not enough. So I have been scanning and replacing trying to narrow it down. Budget is quite thin at this point and my son is a bit discouraged.

Going out to do the leak down test shortly.

It is normal for fuel pressure to be in the sixties while the pump is on and to drop when the pump turns off. While the pump is on your are looking at regulated fuel pressure if the pump and system are in good working order. As soon as the pump turnes off the pressure will drop but must hold 55 or more for 10 min. Now you are checking to see if the system is leaking.

George

It will drop pretty much to zero immediately.

When the pump starts the system is capable of developing 60psi or more but then as soon as the pump quits the system pressure goes to zero? This is at the fuel rail Schraeder on top of the engine?

George

Rusty, no not yet just getting to the garage.

Yes, at the schrader valve.

Repeating this test at the fuel filter output will tell you if the leak is in the tank or the plenum.

George

Oh ya and scratch the air leak theory, it’s the opposite problem - inadequate fuel delivery, but at this point you already know that.

George

so on the output side of the filter, pressure spikes then right down to zero.

This is is a brand new fuel pump! It that really the cause?