Bonneville V8-4.6L VIN Y (2004)
Fuel Injector: Description and Operation
FUEL INJECTORS
The top-feed 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 injector solenoid, which opens a ball valve, allowing fuel to flow past the ball valve, and through a recessed flow director plate. The
director plate has multiple 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 stuck partly open
can cause a loss of pressure after engine shutdown. Consequently, long cranking times would be noticed on some engines.