1. Airflow Control: The throttle body acts as a valve that controls the airflow entering the engine. When the driver presses the accelerator pedal, it opens the throttle body, allowing more air to enter. When the accelerator is released, the throttle body closes, restricting airflow.
2. Engine Speed Control: By controlling the airflow into the engine, the throttle body plays a vital role in regulating the engine speed (RPMs). When the throttle is opened, the air-fuel mixture increases, causing the engine to accelerate. Conversely, when the throttle is closed, the air-fuel mixture decreases, leading to a decrease in engine speed.
3. Idle Speed Control: The throttle body also assists in maintaining the desired engine speed during idling. It ensures that the engine continues to run at a steady RPM when the accelerator pedal is not pressed. This is achieved through an integrated idle air control (IAC) valve or a bypass channel within the throttle body itself.
4. Fuel Injection: In modern engines equipped with electronic fuel injection, the throttle body is integrated with sensors and actuators that communicate with the engine control unit (ECU). This enables precise fuel injection by coordinating the amount of fuel being injected into the engine based on the throttle position and engine operating conditions.
5. Emissions Control: The throttle body contributes to emissions control by helping regulate the air-fuel mixture entering the engine. A properly functioning throttle body ensures that the engine operates within the optimal air-fuel ratio range, reducing the emission of pollutants such as unburnt hydrocarbons and nitrogen oxides.
In summary, the throttle body is a vital component that controls the airflow into the engine, maintains engine speed, assists in idle control, and works in conjunction with modern fuel injection systems to optimize fuel efficiency and reduce emissions.
