Fuel Injection System - Single Unit TBI: Description

The single unit electronic fuel injection (EFI) system consists of 7 major sub-assemblies: Fuel supply system, throttle body injector (TBI) assembly, Idle Air Control System (IAC), Electronic Control Module (ECM), Electronic Spark Timing (EST), data sensors and emission controls. Fuel is supplied to the engine through an electronically pulsed (timed) injector valve located in the throttle body unit on top of the intake manifold. The ECM controls the amount of fuel metered through the injector valve based upon engine demand and efficiency information. The ECM is a digital electronic computer which receives and computes signals from various data sensors.