What is Fuel Pressure at cold start? - Third Generation F-Body Message Boards

taman86 · 09-14-2009, 12:53 AM

My GTA is hard to start, sometimes requiring starting fluid. I have about 30lbs. of FP at cold start, then the FP goes up to 40 after it is running. The car idles OK cold, then is progressively rougher, the warmer it gets. The car cuts out when I step on the gas. The warmer it gets the worse it runs, and the harder it is to start? I think it may be the Fuel Pump, but the FP reading is 40 after it is running. I replaced the fuel filter. I am wondering if maybe I have a miss.

rgarcia63 · 09-14-2009, 02:15 AM

Actually the pressure should be set @ 43.5psi+/- with the key on/engine off, then drop as the vacuum increases, how much depends on the engine, but should increase as rpm increases until it reaches the set pressure. If you don't start the engine the pressure will gradually bleed off over time after the ECM completes the primer cycle for a few seconds.