Does the Holley Fuel Pump Fuel Pressure Regulator work well?
By bjm “bjm” (San Salvador, El Salvador) The Holley 12-804 fuel pressure regulator actually operates in the 1 to 4.5 psi range. It’s the Holley 12-803 that ranges from 4.5 to 9 psi. The unit sits on it’s own chromed mounting bracket that can be attached to the firewall or near the inner fender wells of the engine compartment. Loosening the lock nut on the top and turning the allen head screw, it is possible to adjust the fuel pressure, though you will need a fuel pressure gauge attached to calibrate the setting. To do that, it’s convenient that there are two outlet ports. One can be the fuel outlet to the carburetor. The other can be where the gauge is attached. The fuel inlet from the pump is on the bottom. Each of these ports is a 3/8″ NPT thread, so brass hose fittings can be installed. The second outlet port can be plugged if the gauge is removed, or can be used to feed a double carburetor installation. I understand that the initial factory setting for the fuel pressure is 2.7 psi,
This regulator is used to adjust to fuel pressure requirements of various carburetors and supplies the proper pressure to the needle and seat valve to prevent flooding or drivability problems. This satin finish regulator feature 3/8 pipe thread outlet ports with 7/32″ restriction. It regulates pressure from 4-1/2 to 9 PSI and is designed to work with a single carburetor installation.
