Fuel Injector: Description and Operation

Injector Cross Section:

The fuel injector is an electromagnetic type injection nozzle which injects fuel into the throttle bore according to the signals from the ECM.

When the solenoid coil of the injector is energized by the ECM, it becomes an electromagnet and attracts the plunger. At the same time the needle valve, which is incorporated with the plunger, opens and the injector which is under the fuel pressure injects fuel in a cone-shaped spray. As the lift stroke of the needle valve of the injector is set constant, the amount of fuel injected at one time is determined by the length of time during which the solenoid coil is energized (injection time).