Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator:

GENERAL DESCRIPTION
The fuel pressure regulator is a diaphragm-operated relief valve with fuel pump pressure on one side, and regulator spring pressure and intake manifold vacuum on the other. The function of the regulator is to maintain a constant pressure across the injectors at all times. The pressure regulator compensates for engine load by increasing fuel pressure as engine vacuum drops.

OPERATION
With the ignition "ON" and engine "OFF" (zero vacuum), fuel pressure at the pressure connection should be 284-325 kPa (41-47 psi). If the pressure is too low, poor performance could result. If the pressure is too high, excessive odor and / or Diagnostic Trouble Code (DTC) 43 or 45 may result. Chart A-7 has information on diagnosing fuel pressure conditions.