Fuel Pressure Regulator: Description and Operation

FUEL PRESSURE REGULATOR ASSEMBLY

The fuel pressure regulator is a diaphragm-operated relief valve located in the modular fuel pump and sender assembly. Its principal function is to maintain a controlled pressure at the injectors at all times by regulating fuel flow into the fuel feed line. The injector pulse width varies with the signal from the manifold absolute pressure (MAP) sensor. With the ignition ON and the engine OFF, system fuel pressure at the pressure test connection should be 380-440 kPa (55-64 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) may result. Refer to Fuel System/Testing for information on diagnosing fuel pressure conditions.