Fuel Pressure Regulator: Description and Operation

Typical Fuel Pressure Regulator:

PURPOSE
The fuel pressure regulator controls fuel pressure supplied to the injectors. The regulator also traps fuel during engine shutdown, thus eliminating the possibility of vapor formation in the fuel line, and provides instant restarts and initial idle speed.

OPERATION
Balancing one side of the diaphragm with manifold vacuum maintains a constant fuel pressure drop across the injectors. Fuel in excess of that used by the engine is bypassed through the regulator and returns to the fuel tank.

CONSTRUCTION
The regulator is a spring loaded diaphragm operated relief valve. One side of the diaphragm senses fuel pressure and the other side is connected to intake manifold vacuum.