Grand Prix V6-204 3.4L DOHC VIN X SFI (1995)
Fuel Injector: Description and Operation
Fuel Injector
GENERAL DESCRIPTION
The fuel injector assembly is a solenoid-operated device, controlled by the Powertrain Control Module (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 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 is stuck partly open would cause loss of fuel pressure after engine shut down, so long cranking 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."