Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator Assembly:

PURPOSE:
The function of the regulator is to maintain a constant pressure differential across the injectors at all times.

OPERATION:
The pressure regulator compensates for engine load by increasing fuel pressure as engine vacuum drops. The pressure regulator is mounted at the end of the fuel rail, and is serviced as a complete assembly.

The system operates in an acceptable pressure range of 284-325 kPa (41.0-47.0 psi) with the engine running. If the pressure is too low, poor performance and a Code 44 could result. If the pressure is too high, excessive odor and a Code 45 could result. CHART A-7 has information on diagnosing fuel pressure conditions.

CONSTRUCTION:
The fuel pressure regulator assembly is a diaphragm-operated relief valve with fuel pump pressure on one side, and regulator spring pressure and intake manifold vacuum on the other.