Fuel Injection System

The Fuel Injection System consists of the ECU, all of the engine condition and operating condition sensors, and the injectors. The ECU uses the information from the sensors to determine the proper amount of fuel and the proper time of delivery.

Injector:

The injectors are solenoid operated valves installed in the intake manifold. When the solenoid coil is energized the plunger is retracted. The needle valve that is attached to the plunger is pulled to the full open position and fuel is injected through the valve. When the solenoid is de-energize, spring pressure closes the valve. Since the injection nozzle opening is a fixed size and the fuel pressure is also fixed, the injection amount is determined by the duration time which the needle valve is open.