Fuel Pressure Regulator: Description and Operation

Fuel Pressure Regulator:

PURPOSE
The fuel pressure regulator regulates the fuel pressure supplied to the fuel injectors. It also bypasses and returns excess fuel to the fuel tank.

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. Nominal fuel pressure is established by a spring preload applied to the diaphragm. It balances one side of the diaphragm with manifold pressure to maintain a constant fuel pressure drop across the fuel injectors.