Sierra 1500 4WD V8-5.3L VIN Z Flex Fuel (2005)
Fuel Pressure Regulator: Description and Operation
Fuel System (Cab Chassis)
FUEL PRESSURE REGULATOR ASSEMBLY
The fuel pressure regulator is a vacuum operated diaphragm relief valve. The diaphragm has fuel pressure on one side and regulator spring pressure and
intake manifold vacuum on the other side. The fuel pressure regulator compensates for changes in intake manifold vacuum by changing the fuel pressure.
In this way, the fuel pressure regulator maintains a constant pressure differential across the fuel injectors under all operating conditions.
