Fuel Supply System

Fuel pressure regulator:-

Maintains an even supply pressure to the injectors.

Single point systems incorporated in the throttle body.

Multi-point systems fitted downstream of the injectors.

Operation:-

The regulator body is divided into two chambers by a diaphragm.

The upper (spring) chamber is connected, by vacuum hose, to the inlet manifold downstream of the throttle valve

The lower chamber receives pressurized fuel.

When the fuel supply pressure exceeds the pre-set regulator pressure the diaphragm valve opens and allows the excess fuel to flow back to the tank.

The vacuum exerted on the upper chamber modifies the spring pressure and ensures that the pressure difference between the fuel chamber and the inlet manifold is constant

Injector:-

Single point systems the injector sprays fuel into the throttle body.

Multi-point systems the injectors spray fuel into the inlet manifold.

Operation:-

Electronically controlled injectors are opened by an integral solenoid single point, multi point, which responds to signals from the ECM.

The fuel is injected in a fine spray, in order to ensure thorough mixing with the intake air.

External resistors may be provided for each injector.

Injectors for mechanical systems (KE-Jetronic and derivatives) have a spring loaded valve operated by fuel.