The ECU determines precisely how much fuel needs to be delivered by the injector by monitoring the engine sensors. B.
The ECU turns the injectors on for a precise amount of time, referred to as injection pulse width or injection duration, to deliver the proper air-fuel ratio to the engine. C.
Its components are: engine sensors, electronic control unit, fuel injector assemblies and related wiring. D.
The basic function of the ECU is to control the pulse width of the injector.