Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator:

The fuel pressure regulator is a diaphragm-operated relief valve with injector pressure on one side and manifold pressure on the other. The function of the regulator is to maintain a constant pressure at the injectors at all times. The pressure regulator also compensates for engine load by increasing fuel pressure, when it sees low engine vacuum.

The pressure regulator is mounted on the fuel rail, and is serviced separately.

The system operates in an acceptable pressure range of 211-304 kPa (30.5-44.0 psi) with the engine running. If the pressure is too low, poor performance could result. If the pressure is too high, excessive odor and a Code 45 may result. CHART A-7 has information on diagnosing fuel pressure conditions.