K 2500 Truck 4WD V8-454 7.4L VIN J SFI (1997)
Fuel Pressure Regulator: Description and Operation
Locations
Description
The fuel pressure regulator is a diaphragm-operated cartridge relief valve with the fuel pump pressure on one side and the regulator spring pressure and
intake manifold vacuum on the other. A retainer holds the fuel pressure regulator.
Function
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 the fuel pressure as engine vacuum drops.
With the ignition ON leaving the engine off (zero vacuum), the fuel pressure at the pressure test connection should be 385-430 kPa (56-62 psi). If the
pressure is too low, poor performance could result. If the pressure is too high, excessive odor may result. The Fuel System Diagnosis has information on
diagnosing fuel pressure conditions. Refer to Fuel System Diagnosis. Refer to System Diagnosis / Diagnostic Tables. See: Computers and Control
Systems/Testing and Inspection