Fuel Injectors

Fuel injectors are electric solenoid valves controlled by PCM. PCM determines when and length of time (pulse width) injectors should operate by switching ground path on and off. During start-up, battery voltage is supplied to injectors through ASD relay. On some models, battery voltage is supplied by charging system once engine is operating. When ground is supplied to injector by PCM, armature and pintle inside injector move a short distance against spring and open a small orifice. Since fuel is under high pressure, a fine spray is developed.