* Fuel metering: The carburetor mixes fuel and air. A throttle body only controls the air.
* Fuel delivery: The carburetor provides the fuel. You'll need a completely different fuel delivery system with a throttle body, likely involving a fuel pump, injectors, and fuel rail.
* Engine management: A carburetor is a relatively simple, passive device. A throttle body injection system requires a sophisticated engine control unit (ECU) to manage fuel injection timing, air/fuel ratio, ignition timing, and other parameters. This usually means significant wiring changes.
* Intake manifold: The intake manifold for a carburetor is designed differently than one for throttle body injection. You'll likely need a new intake manifold.
* Sensors: Throttle body injection relies on various sensors (e.g., MAP sensor, oxygen sensor, crankshaft position sensor) to feed data to the ECU. These will need to be added.
In short, converting a carburetor engine to throttle body injection is a major engine overhaul, requiring significant mechanical and electrical modifications. It's a project best left to experienced mechanics or serious engine enthusiasts with the right tools and knowledge. The cost of parts and labor would often far exceed the value of the vehicle, except in cases where the engine is valuable or for a specific high-performance project.
