Envoy 2WD V8-5.3L VIN P (2004)
Fuel Pressure Regulator: Description and Operation
Fuel System (Without Returnless Fuel System)
FUEL PRESSURE REGULATOR ASSEMBLY
The fuel pressure regulator is a vacuum-operated diaphragm relief valve with fuel pump pressure on one side, and with regulator spring pressure and
intake manifold vacuum on the other side. The fuel pressure regulator maintains a constant pressure differential across the fuel injectors at all times. The
fuel pressure regulator compensates for engine load by increasing the fuel pressure when the engine vacuum drops.
