Fuel Pressure Regulator

The fuel pressure regulator is located in the fuel supply manifold downstream from injectors. Excess fuel not required by injectors passes through regulator and returns to fuel tank through a fuel return line.

The regulator is a diaphragm operated relief valve. One side of diaphragm senses fuel pressure and other side senses intake manifold vacuum. Nominal fuel pressure is established by an applied spring preload on diaphragm. Balancing one side of diaphragm with manifold pressure maintains a constant fuel pressure across injectors.