Fuel Pressure

[Mesa Mike]

I have a EFI 302 set up. When I turn on the key the fuel pump pressurizes the system and holds steady at 41 PSI. When I turn the key off the pressure guage goes to zero. It sometimes takes time to re-presurize and start. I replaced the fuel pump without any change. Any ideas? Fuel regulator? Shouldn't the fuel pressure hold steady for some time after you shut off the system?

Thanks,

Mesa Mike

[Dan Golub]

I have a EFI 302 set up. When I turn on the key the fuel pump pressurizes the system and holds steady at 41 PSI. When I turn the key off the pressure guage goes to zero. It sometimes takes time to re-presurize and start. I replaced the fuel pump without any change. Any ideas? Fuel regulator? Shouldn't the fuel pressure hold steady for some time after you shut off the system?

Thanks,

Mesa Mike

Hi Mike,

Yes, the fuel pressure should hold for at least 1 minute or so, if not longer. I believe there is a check valve in the fuel pump that is suppose to allow pressure to be held in the system. However, since the stock 302 EFI is a return style system, your regulator could be causing the fuel to return to the tank too quickly. If it is the stock regulator, take the vacuum line off and attache a vacuum pump to the regulator to try and actuate the diaphragm in the regulator. If the diaphragm is ruptured, fuel will leak into the intake manifold via the vacuum line connected to the regulator. Otherwise, just make sure you don't have any small leaks. You already replaced the fuel pump, which rules out a bad check valve.

Thank You

Dan @ FFR