K 2500 Truck 4WD V8-305 5.0L VIN M SFI (1998)
Fuel Pressure Regulator: Description and Operation
Fuel Pressure Regulator Assembly, Located In Fuel Meter Assy Inside Intake Manifold
DESCRIPTION
The fuel pressure regulator (1) 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 (2) holds the fuel pressure regulator.
PURPOSE
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.
OPERATION
With the ignition ON leaving the engine off (zero vacuum), the fuel pressure at the pressure test connection should be 415-455 kPa (6O-66 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