Fuel Injector: Description and Operation

PURPOSE
The six fuel injectors are electro-mechanical devices which both meter and atomize fuel delivered to the engine. They are mounted in the cylinder head pockets and positioned so that their tips are directing fuel just before the engine intake valves.

COMPONENTS
The fuel injector valve body consists of the following:
- solenoid
- needle and valve assembly
- director/metering plate

OPERATION
An electrical control signal from the Powertrain Control Module (PCM) activates the fuel injector solenoid, causing the needle to move inward, off the seat, allowing the fuel to flow. Since the fuel injector flow orifice is fixed and the fuel pressure drop across the injector tip is constant:
- fuel flow to the engine is regulated by the length of time the solenoid is energized.
- atomization of the fuel is obtained by a director/metering plate where the fuel separates.