Fuel Pressure Regulator
The fuel pressure regulator controls fuel pressure to 39 psi (2.74 kg/cm2 ) across the fuel injectors. Excess fuel is returned to the tank through a return line. The pressure regulator is mounted on the charging main body so as to nullify the effects of the supply line pressure drops. It is not sensitive to back pressure in the return line to the tank.
The pressure regulator also maintains fuel supply pressure upon engine and fuel pump shut down. Maintaining fuel pressure prevents fuel line vapor formation which allows for rapid restarts and stable idle operation.