Fuel Pressure Regulator
Fuel pressure regulator is attached to fuel supply manifold assembly downstream of fuel injectors. It regulates fuel pressure supplied to injectors. Regulator is diaphragm operated relief valve in which 1 side of diaphragm senses fuel pressure and other side is subjected to intake manifold pressure.
Nominal fuel pressure is established by spring preload applied to diaphragm. Balancing 1 side of diaphragm with manifold pressure maintains constant fuel pressure drop across injectors. Excess fuel is by-passed through regulator and returned to fuel tank.