Operation

OPERATION

Operation

When the ignition switch is moved to position lithe fuel pump relay in the engine compartment fusebox is energized by the ECM. Battery voltage is supplied from the fuel pump relay to the fuel pump which operates. If engine cranking is not detected by the ECU within a thirty second period, the ECU will 'time-out', de-energizing the fuel pump relay.

The fuel pump draws fuel from the swirl pot and pumps it along the fuel feed pipe to the injector fuel rail on the engine. When the pressure in the fuel feed line reaches 3.5 bar (50 lbf.in) the fuel pressure regulator opens and relieves pressure by directing fuel back into the swirl pot. The pressure regulator is constantly opening and closing to maintain the pressure in the fuel feed pipe and the fuel rail at 3.5 bar (50 lbf.in).

The pressure is felt at each of the eight injectors connected to the fuel rail. The ECM controls the injection timing and energizes each injector to allow a metered amount of fuel at pump pressure to be injected into the inlet tract of the inlet manifold. The atomized fuel from the injector is mixed with air from the inlet manifold before passing into the cylinder.