Fuel Injector: Description and Operation

Fig. 1 Digital electronic fuel injection unit:

The injector unit, Fig. 1, is composed of two major assemblies; a throttle body and a fuel body.
The throttle body contains an Idle Speed Control (ISC) control assembly and a Throttle Position Sensor (TPS). The throttle body portion of the injector unit may contain ports located at, above, or below the throttle valve. The ports are used to produce the vacuum signals for the canister purge system and the Manifold Absolute Pressure (MAP) sensor.
The fuel body portion of the injector unit contains a fuel meter cover with integral pressure regulator and a fuel injector to supply fuel to the engine.