Fuel Injector: Description and Operation

Fuel Flow Through Lower Manifold And Injectors:

Fuel Injector Cross-Section View:

DESCRIPTION
The Bottom Feed Port (BFP) Injector Assembly is a solenoid-operated device, controlled by the Electronic Control Module (ECM), that meters pressurized fuel to a single engine cylinder. An injector that remains partly open could cause loss of pressure after engine shut down. Consequently, long cranking times would be noticed on some engines. Dieseling also could occur because some fuel could be delivered to the engine after the ignition is turned "OFF."

OPERATION
The ECM energizes the injector solenoid, which opens a ball valve, allowing fuel to flow past the ball valve, and through a recessed flow director plate. This plate has machined holes that control the fuel flow, generating a conical spray pattern of finely atomized fuel at the injector tip. Fuel is directed at the intake valve, causing it to become further atomized and vaporized before entering the combustion chamber.