Fuel Injection System - Dual Unit TBI: Description

The Model 220 Throttle Body Injection (TBI) unit is computer-controlled and uses a pair of fuel injectors to deliver fuel to the engine. The Electronic Control Module (ECM) changes fuel delivery (air/fuel ratio) by controlling fuel injector operation.

The ECM looks at voltages received from several sensors and determines how much fuel is required. Because of the constant measuring and adjusting of fuel delivery, a closed loop system is used.

The fuel control system consists of the following components: Throttle Body Injection (TBI) unit, fuel injectors, fuel pressure regulator, Idle Air Control (IAC) valve, fuel pump and fuel pump relay.