Fuel Pressure Regulator: Description and Operation

The fuel filter/fuel pressure regulator is installed in the fuel feed pipe ahead of the fuel injection system. The paper filter element of the fuel filter traps particles in the fuel that may damage the fuel injection system. The fuel filter/fuel pressure regulator housing is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There is no service interval for fuel filter replacement. Replace a restricted fuel filter.

The fuel pressure regulator is a diaphragm operated relief valve. A software bias compensates the injector on-time because the fuel pressure regulator is not referenced to manifold vacuum. The injector pulse width varies with the signal from the MAP sensor. With the ignition ON and the engine OFF, system fuel pressure at the pressure test connection should be 380-420 kPa (55-61 psi). If the pressure is too low, poor performance could result. If the pressure is too high, excessive odor and a Diagnostic Trouble Code (DTC) P0132, P0152, P0172 or P0175 may result. Refer to Fuel System Diagnosis for information on diagnosing fuel pressure conditions.