Throttle Body: Description and Operation

The Model 220 TBI unit consists of three assemblies:
^ Fuel Meter Cover. Pressure regulator.
^ Fuel Meter Body. TBI fuel injector assemblies.
^ Throttle Body
- Two throttle valves to control air flow into the engine.
- Idle air control (IAC) valve.
- Throttle position (TP) sensor.
- Vacuum ports located at, above, or below the throttle valves, to generate vacuum signals to various controls and accessories.