irratic fuel pressure

[Clarence]

Any suggestions on irratic fuel pressure indication on a 1994 M20J?  The fuel pressure indication drops off as engine RPM is increased and the alternator comes on line. We have cleaned and checked all grounds, re routed the alternator wiring further from the transduced.  With alternator off, keying the microphone  causes the indication to spike up to above red line.

Thanks,

Clarence

[Jeff_S]

My fuel pressure gauge is similary erratic. I think the main connectors get corroded and come loose...when I gently press on the screw holding it in things stabilize. I have a small screwdriver that I keep handly to periodically tighten it and the problem goes away. Since I have a JPI I don't worry about it too much. That instrument, and the big fan in front, will tell me if I have a fuel problem.