Pressure Regulator

Pressure regulator is located downstream from fuel injector, on the throttle body. Regulator is equipped with a spring loaded rubber diaphragm which covers a fuel return port. Fuel flow past the injector enters regulator, and is restricted from flowing back to tank by blocked return port. When fuel pressure reaches 36 psi (2.5 kg/cm² ), spring is compressed enough to allow fuel into return line.

Further control of fuel pressure is provided by a vacuum line from regulator to a vacuum port located in throttle body, above the throttle plate. As venturi vacuum increases, less pressure is required to introduce the same amount of fuel into air stream. This vacuum assist allows additional fine tuning of fuel pressure under all operating conditions.