Fuel Injector: Description and Operation

Fuel Injector:

Purpose
- Allows PCM to precisely control the amount of fuel injected.
- Atomizes fuel for more complete combustion.
- Sprays fuel into intake manifold, above intake ports, in an even, conical pattern.

Operation
- When an injector solenoid is energized, the plunger is retracted, lifting needle valve off seat, allowing the pressurized fuel to spray into the intake manifold.
- When the solenoid is de-energized spring pressure closes valve.

NOTE: Since the injector nozzle is a fixed size and fuel pressure is regulated (at 48 psi), the amount of fuel injected changes only when the amount of time the injector is energized per cycle changes.
- This period of time is called "injector pulse width".