Fuel Pressure Regulator

The cartridge-type fuel pressure regulator (1) is a diaphragm-operated relief valve (6) with fuel pump pressure on one side, and regulator spring (2) pressure, and intake manifold vacuum on the other side. The regulator's function is to maintain a constant fuel pressure across the injectors at all times. The pressure regulator compensates for engine load by increasing fuel pressure as engine vacuum drops. The cartridge regulator is serviced as a separate component. When servicing the fuel pressure regulator, insure that the O-ring backup (3), the large O-ring (4), the filter screen (5), and the small O-ring (7) are properly placed on the pressure regulator.

If the fuel pressure is too low, reduced performance and a DTC P0171, may result. If the pressure is too high, excessive odor and a DTC P0172 may result.