General

Fig. 2 Electronic engine control & related components:

The ECA detects the engine operating, driveability conditions and exhaust gas oxygen content from various switches, sensors and components, then controls the amount of injected fuel into the engine, Fig. 2. The ECA also has some control over the evaporative emission, idle-up, ignition and deceleration systems.

Fig. 1 Electronic fuel injection system:

The electronic fuel injection system, Fig. 1, is classified as a multi-point, pulse fuel injection system. This system supplies the engine with the air/fuel mixture necessary for proper combustion. An air induction system and fuel injection system work in conjunction with an electronic engine control system which consists of various sensors, switches and an electronic control assembly (ECA) unit. All of the sensors and switches are connected to the ECA which interprets the data it receives and computes fuel injector operating duration.
Basic fuel requirement for the engine is determined by data supplied to the ECA by the vane air flow meter which measures the amount of air being drawn into the engine. Other sensors and switches are used to measure air temperature, atmospheric pressure, coolant temperature, engine speed and exhaust oxygen content. The sensors and switches detect any changes in the operating conditions and transmit corresponding signals to the ECA. This permits proper control over the opening duration of the fuel injectors to maintain optimum exhaust emission control and engine performance for all operating conditions.