Fuel Injector: Description and Operation
Fig 2 Fuel Injector:

Fig 3 Fuel Injector Location -- Typical:

Fuel Injector - Cutaway View:

The fuel injectors are 12 ohm electrical solenoids (Fig. 2). 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 a hollow cone. The spraying action atomizes the fuel, adding it to the air entering the combustion chamber. The injectors are positioned in the intake manifold.
The injectors are positioned in the intake manifold with the nozzle ends directly above the intake valve port (Fig. 3).