Fuel Injector: Description and Operation

Fuel Injector Typical:

FUNCTION

The fuel injectors are solenoid operated valves that deliver fuel, in a metered amount, to the combustion chambers of individual cylinders.


OPERATION

When the solenoid coil is energized (on), the plunger is retracted lifting the needle valve off its seat, allowing fuel to be injected into the combustion chamber. When the solenoid is de-energized (off) spring pressure closes the valve.

This vehicle uses bottom fed fuel injectors. The bottom of the injector is fed with fuel from a passage in the intake manifold.

The ASD relay supplies voltage to the fuel injectors. The PCM controls the ground paths to fuel injectors, by switching the ground path on and off. The PCM can fine tune fuel delivery adjusting injector pulse width (on time).