Fuel Pressure

[rayy]

I recently did a 6.2 swap in my 72 Vette. I used the GMPP harness and the car has ran well over the last 4 months or so. Just recently the car will start to loose power as if the car is running out of fuel the car will just eventually die. You can shut the car off and restart it and it will run fine for about 2-3 minutes and then it starts all over. I checked the fuel pressure at the rail and it was close to 80 psi which I know is to high. At that point I replaced the corvette style regulator that I have on the car with a new one. The pressure gauge stopped working at that point so I do not know the pressure after the regulator replacement. I did go and drive the car with only the same thing to happen. Any ever have this issue before ? Thought for sure with the pressure running at close to 80 PSI that the regulator would fix it. I plan on trying another gauge tomorrow to see what the pressure is now.

[nokones]

If your fuel pressure increase under throttle, which the regulator is suppose to that, the pressures you are running may be causing the injectors to worker and may not be opening. Also check your air intake to make it is not collapsing under throttle.

[CarlC]

The C5 Corvette fuel pressure regulator/filter is not manifold referenced. Hence, the fuel pressure does not change with engine manifold pressure.

A new good gauge is needed to determine what is going on. Watch the presure at idle. If it falls after several minutes it's likely the pump.

[rayy]

Well found the problem to be tank no venting properly there for the return line was backing up.