Operation CHARM: Car repair manuals for everyone.

Fuel Injector





Fuel Injector
The fuel injector assembly is a solenoid-operated device, controlled by the PCM, that meters pressurized fuel to a single engine cylinder. The PCM energizes the fuel injector solenoid (3), which opens a ball valve (1), allowing fuel to flow past the ball valve, and through a recessed flow director plate (2) at the injector outlet.

The director plate has machined holes that control the fuel flow, generating a conical spray pattern of finely atomized fuel at the injector tip. Fuel from the tip is directed at the intake valve, causing it to become further atomized and vaporized before entering the combustion chamber.

A fuel injector that is stuck partly open would cause loss of pressure after the engine is shut down, so long crank times would be noticed on some engines. Dieseling could also occur because some fuel could be delivered to the engine after the ignition is turned OFF.