Fuel Injectors

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

The fuel injector is an electromagnetic (solenoid) type injection nozzle which injects fuel into the intake port of the cylinder head according to the signals from the powertrain control module (PCM). There are 4 fuel injectors, one for each cylinder, located between the intake manifold and the fuel rail.

The PCM energizes the solenoid coil of the fuel injector, generating an electromagnet field that attracts the solenoid plunger. The needle valve, which is incorporated with the solenoid plunger, is opened by the movement of the solenoid plunger. The opening of the needle valve allows fuel that is under pressure to disperse thorough a four hole plate into a cone shaped pattern. Because the stroke of the needle valve in the fuel injector is set constant, the amount of fuel injected at one time is determined by the pulse width injection time (length of time the solenoid coil is energized).