Fuel pressure problem, Please help!

**Turbohawklt1** · 07-21-2009, 04:58 PM

97 lt1, turn the key on, i can hear the pump run for a couple of seconds, my under hood guage goes up to about 20psi and then instantly starts going back to zero, it will not kick back on until you take the key out and repeat, pressure stays at zero when you crank it as well. any input would be great, Thanks

***Fastbird*** · 07-21-2009, 05:51 PM

Possible bad pump (doubtful because you can hear it priming). Check for an internal leak (line popped off or cracked before exiting the tank), leaky fuel injector, bad fuel pressure regulator.

**Turbohawklt1** · 07-21-2009, 06:06 PM

Thanks for the input sean, i was thinking it may be a loose hose in the tank, i checked the vacuum line at the intake for the fpr and its dry and does'nt smell like gas, is it possible if the pressure is at zero and trying to start the car will the pcm still send a signal to the opti to send spark to the plugs?

***Fastbird*** · 07-21-2009, 08:23 PM

Yes. The computer doesn't read the fuel pressure. Is the pump running while you're cranking??? Hard to verify I know, but it would help. Even if it wasn't running your car should build pressure and have enough to vacuum feed the rails. I had a DEAD pump that I was driving around on because it was vacuum feeding.

It really sounds like you need to pull the pump and look at the line.

**Turbohawklt1** · 07-27-2009, 02:37 PM

Pulled the pumps twin gss341's, no loose, tore or damaged lines, everything looks normal as far as i can tell, can the pump still be bad if it kicks on but won't build pressure, when trying to start it the pump isnt running, it wont run again until the key is taken out and put back in, then its just a couple seconds and goes to 20 psi and back to zero in a matter of about 20 seconds, Thanks in advance for your help.