Caprice V8-265 4.3L VIN W MFI (1995)
Fuel Pressure Regulator: Description and Operation
Pressure Regulator
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 regulator's function is to maintain a constant pressure differential across the injectors at all times. The pressure regulator
compensates for engine load by increasing fuel pressure as engine vacuum drops.
With the ignition "ON" and engine "OFF" (zero vacuum), system fuel pressure at the pressure test 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 a Diagnostic Trouble Code (DTC) 45/65 may result.
CHART A-7 has information on diagnosing fuel pressure conditions.
