Hi all,

My 88 GTA with a 5.7L has an issue starting where I believe it is my fuel pressure. It cranks for 15-20 seconds before firing. The fuel pump relay is turning on the fuel pump when the key is on, and if it is cycled 5-7 times before trying to crank it starts easier. This tells me the fuel pump relay is fine and the fuel pump is turning on before the oil pressure turns it on, but I'm loosing pressure somewhere.I need to get a fuel pressure gauge to take pressures on the Schrader valve to confirm pressures, but while I'm away at work I'm looking at how to troubleshoot if the check valve in the fuel pump is no good, or if it could potentially be a fuel pressure regulator, or leaky injector.

Any help would be appreciated!

Thanks

 

Yup
KOEO pressure comes up immediately Relay is OK
If you do not get >40PSI KOEO pump may be bad, regulator, or injector.
Check for fuel in the vacuum line of the FPR... if there is fuel it is bad.
Then do a 30 min leak down test
If after 5min you have almost no pressure left, you need to crimp the return line... if it still falls you have an injector leaking or stuck open.


Also, on the 88 it has a Cold Start Injector. Need to verify it is working.

There are more test to run, not meaning this to be comprehensive... just a short list to get started.

Could be as simple as a clogged fuel filter as well. Good maintenance item that is pretty easily replaced for troubleshooting.