Fuel Injector
On turbo models, 4 injectors are mounted on a fuel rail, supplying the intake manifold with the proper fuel supply.
Power to the injector(s) is supplied by the SMEC, which determines when and how long the injector should operate. When electric current is supplied to the injector, an integral armature and pintle valve move a short distance against a spring, opening a small orifice.
Fuel supplied to the injector is forced around the pintle valve and through this opening, resulting in a fine spray of fuel in the shape of a hollow cone. A constant pressure drop is maintained across the injector (by the pressure regulator). The length of time that this opening is maintained (injector "on" time) determines the amount of fuel entering the engine and, therefore, the air/fuel ratio.