Fuel Pressure Regulator: Description and Operation

NOTE: The Flexible Fuel (FF) fuel pressure regulator operates the same as the unleaded gasoline fuel pressure regulator. However, the internal components are strictly modified to be methanol and ethanol compatible.

The fuel pressure regulator:
- is attached to the fuel injection supply manifold downstream of the fuel injectors.
- regulates the fuel pressure supplied to the fuel injectors. Nominal fuel pressure is established by a spring preload applied to the diaphragm.
- is a diaphragm-operated relief valve in which one side of the diaphragm senses fuel pressure and the other side is subjected to intake manifold pressure.
- balances one side of the diaphragm with manifold pressure to maintain a constant fuel pressure drop across the fuel injectors.
- bypasses and returns excess fuel to the fuel tank.