K 3500 Truck 4WD V8-454 7.4L VIN N TBI (1995)
Fuel Pressure Regulator: Description and Operation
TBI Operation
PURPOSE
The regulator's function is to maintain a constant fuel pressure drop across the injector at all times.
OPERATION
Fuel pressure is regulated by the difference between fuel pump pressure acting on one side of the diaphragm and the force of the calibrated spring
(and air cleaner air pressure) acting on the other side. The system operates in an acceptable pressure range of 179 to 220 kPa (26 to 32 psi).
If the fuel pressure is too low, poor performance could result. If the pressure is too high, excess emissions and unpleasant exhaust odor may result.
CONSTRUCTION
The pressure regulator is part of the fuel meter assembly, and contains an air chamber and a fuel chamber that are separated by a
diaphragm-operated relief valve and a calibrated spring.
