Fuel Injector: Description and Operation

Fig. 4 Fuel Injector:

Fig. 5 Fuel Injector Location - Typical:

The fuel injectors are electrical solenoids (Fig. 4). The injectors are positioned in the cylinder heads with the nozzle ends directly above the intake valve port (Fig. 5). Fuel injectors are not interchangeable between engines.

The injector contains a pintle that closes OFF an orifice at the nozzle end. When electric current is supplied to the injector, the armature and needle move a short distance against a spring, allowing fuel to flow out the orifice. Because the fuel is under high pressure, a fine spray is developed in the shape of 2 streams. The spraying action atomizes the fuel, adding it to the air entering the combustion chamber.