Fuel Pressure Regulator: Description and Operation

Pressure Regulator Control System:

PURPOSE
The pressure regulator maintains fuel pressure at specified levels for efficient engine operation. The (fuel) pressure regulator is also part of the pressure regulator control (PRC) system. The PRC system enables the powertrain control module engine (PCME) to raise fuel pressure during hot restarts which helps prevent "vapor lock".

OPERATION
The pressure regulator uses a spring loaded diaphragm connected to manifold vacuum through a hose on the PRC solenoid valve. 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 PRC solenoid valve temporarily cuts vacuum to the pressure regulator.