Fuel Pressure Regulator
The pressure regulator mounts to the fuel charging main body near the rear of the air horn surface. The regulator is located strategically to avoid the effects of the supply line pressure drops. Its design is such that it is not sensitive to BACK PRESSURE in the return line to the tank.
A second function of the pressure regulator is to maintain fuel supply pressure upon engine and fuel pump shutdown. The regulator functions as a downstream check valve and traps the fuel between itself and the fuel pump.
The maintenance of fuel pressure upon engine shutdown precludes fuel line vapor formation. It also allows for rapid restarts and stable idle operation immediately after restart. It regulates the fuel pressure to the injector nozzles at a constant nominal value of 39 psi (2.7 kg/cm2 ).