Camaro RS V8-305 5.0L VIN E TBI (1990)
Fuel Pressure Regulator: Description and Operation
The pressure regulator is an integral part of the fuel meter cover, and contains an air chamber and a fuel chamber that are separated by a
diaphragm-operated relief valve and a calibrated spring. The function of the regulator is to maintain constant pressure across the injector at all times.
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 pressure) acting on the other side. The system operates in an acceptable pressure range of 62 to 90 kPa (9 to 13 psi). The fuel meter cover
includes a bleed that relieves system pressure when the engine is turned "OFF". The bleed also helps purge vapors from the injector and regulator after a
hot restart.
If the pressure regulator in the TBI supplies pressure which is too low (below 62 kPa or 9 psi), poor performance could result. If the pressure is too
high, excess emissions and unpleasant exhaust odor may result.
