Fuel Filter: Description and Operation

The fuel filter/fuel pressure regulator is located on the fuel feed pipe, between the fuel pump and the fuel injectors. The paper filter element 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. The fuel pressure regulator maintains a constant pressure differential across the injectors at all times. 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 Manifold Absolute Pressure (MAP) sensor.