Fuel Pressure Regulator: Description and Operation

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.
- 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 vacuum. Nominal fuel pressure is established by a spring preload applied to the diaphragm.
- 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.