Fuel Pressure LOW - Third Generation F-Body Message Boards

jamieschott · 09-10-2009, 10:20 PM

Looking for some suggestions or help here.

I have a 92 FIRST Injected 383 here. Stock TPI computer with some tuning done. Any way, vehicle was idling the other day for awhile, enough to get warm enough for fan to kick on and off twice. Then the engine just shut down like someone had turned the key off.

Thought it was the ign coil but since replaced it with new stocker and still no fire with out help. Help meaning giving it gas after it starts to keep it started. Wasnt able to see what fuel pressure was till tonight.

When key is on engine off, it jumps to about 5psi , then quickly drops to 0psi. while attempting to crank engine it will rise to 7-10 psi and hover while cranking. shortly after done cranking pressure will drop to 0psi.

here is what has me stumped. the fuel pump primes. I guess that was said when i said the pressures earlier. i checked voltage at fuel pump and it was 11.5 volts with key on.

the pump is making a high pitched whine during the priming that hadnt existed before. it was quieter than it is now.

any thoughts?

jkris53406 · 09-10-2009, 11:25 PM

Sounds like the pressure regulator to me. Pinch the rubber return line and prime it again to see if there is pressure. Good luck

jamieschott · 09-10-2009, 11:35 PM

it is an aftermarket apfr, and im using braided line from the frame rail lines if that has anything to do with it

jamieschott · 09-12-2009, 06:26 PM

Pulled Fuel pump out and discovered that it was broke... Check valve didnt work either. Not to bad for a pump that only had 350 miles on it.

Replaced pump and all is well. Thanks to that helped

MTXaudioSYSTM · 09-13-2009, 05:46 PM

yeah i was going to say its the fuel pump but you already figured it out. goood job