Fuel Injector: Description and Operation

MFI Fuel Injector Cutaway:

The MFI injector assembly is a solenoid operated device, controlled by the Engine Control Module (ECM), that meters pressurized fuel to a single engine cylinder. The ECM energizes the solenoid to a normally closed ball valve. This allows fuel to flow into the top of the injector, past the ball valve, and through a recessed flow director plate at the injector outlet. The director flow plate has six machined holes that control fuel flow, generating a conical spray pattern of finely atomized fuel at the injector tip. Fuel at the tip is directed at the intake valve, causing it to become further atomized and vaporized before entering the combustion chamber.