Cutlass Ciera L4-2.2L VIN 4 (1995)
Fuel Injector: Description and Operation
Bottom Feed Type,MFI Injector Assembly Cross-Section View
PURPOSE
The bottom feed MFI injector assembly is a solenoid-operated device, controlled by the Powertrain Control Module (PCM), that meters
pressurized fuel to a single engine cylinder.
OPERATION
The PCM 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.
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."
