Fuel Pressure Regulator: Description and Operation

Pressure Regulator Control System:

PURPOSE
Maintains fuel pressure at specified levels for efficient engine operation. Regulator is also part of the system that permits the PCME to raise fuel pressure to prevent percolation during hot restart.

LOCATION
Rear end of fuel rail.

OPERATION
Regulator uses a spring loaded diaphragm connected to manifold vacuum via a hose. Variations in manifold vacuum resulting from changes in engine load and speed cause fuel pressure to vary as needed to compensate for operating conditions.
To prevent fuel percolation during certain hot restart conditions, the PCME controlled pressure regulator solenoid valve temporarily cuts vacuum to the pressure regulator.