* Throttle Body: Controls the amount of air entering the engine. It's a mechanical or electronic valve that regulates airflow.
* Fuel Injectors: Inject a precise amount of fuel into the engine based on the engine's needs. The amount of fuel is determined by the Engine Control Unit (ECU) and is based on various factors like engine speed, load, air temperature, and the position of the throttle body (among others).
The relationship is indirect: The ECU uses the throttle position sensor (TPS) in the throttle body to determine the driver's demand for power. This information, along with other sensor data, is used to calculate the appropriate amount of fuel to inject. So, the throttle body's position *influences* the fuel injector pulse width (the length of time the injectors are open), but it doesn't *directly* control it. The ECU is the intermediary that manages this relationship.
