Silhouette V6-191 3.1L VIN D TBI (1995)
Fuel Pressure Regulator: Description and Operation
TBI 220 Fuel Flow Diagram
The fuel 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 calibrated spring. Its function is to maintain constant pressure drop 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 intake pressure) acting on the other side. The system operates in an acceptable pressure range of 70 to 82 kPa (10 to 12 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 Throttle Body Fuel Injection (TBI) supplies pressure which is too low (below 70 kPa or 10 psi), poor performance
could result. If the pressure is too high (above 82 kPa or 12 psi), excess emissions and unpleasant exhaust odor may result.
