Fuel Pressure Regulator
The fuel pressure regulator is attached to the fuel supply manifold assembly downstream of the fuel injectors. It regulates the fuel pressure supplied to the injectors. The regulator is a diaphragm operated relief valve. One side of the diaphragm senses fuel pressure. The other side is subjected to intake manifold pressure.
The nominal fuel pressure is established by a spring preload applied to the diaphragm. Balancing one side of the diaphragm with manifold pressure maintains a constant fuel pressure drop across the injectors. Excess fuel not used by the engine is by-passed through the regulator and returns to the fuel tank.