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 one side of diaphragm senses fuel pressure and other side is subjected to intake manifold pressure.
Fuel pressure is controlled by spring preload applied to diaphragm. Balancing one side of diaphragm with manifold pressure maintains constant fuel pressure at injectors. Excess fuel is by-passed through regulator and returned to fuel tank.