Fuel Pressure Regulator: Description and Operation

Description:

DESCRIPTION
The fuel pressure regulator is a diaphragm operated relief valve with fuel pump pressure on one side and regulator spring pressure on the other side. The fuel pressure regulator is vented to atmosphere. A software bias is used to compensate injector on-time because the regulator is not referenced to manifold vacuum. The pressure across the injectors varies with the signal from the MAP sensor.

OPERATION
With the ignition ON and the engine OFF, system fuel pressure at the pressure test connection should read 380-420 kPa (55-61 psi). If the pressure is too low, poor performance could result. If the pressure is too nigh, excessive odor and a Diagnostic Trouble Code (DTC) P0132, P0152, P0172 or P0175 may result. The Fuel System Diagnosis table has information on diagnosing fuel pressure conditions. Refer to Computers and Control Systems / Testing and Inspection / Procedures / Diagnostic Tables / System Diagnostic Tables / Fuel System Diagnosis.