Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator:

PURPOSE
The fuel pressure regulator is mounted on the fuel injection supply manifold downstream of the fuel injectors. It regulates the fuel pressure supplied to the fuel injectors.


OPERATION
The fuel pressure regulator 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. It operates as follows:

- 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.