What is the function of the throttle body?
2 Answers
The throttle body has many functions, mainly including the following aspects: automatically adjusting to correct the intake function; controlling the operation of the engine assembly (the idle switch inside the engine is working); controlling the flap, and through the operation of the sensor, regulating the amount of intake air to enhance power. The throttle body is a controllable valve that regulates the air entering the engine. After the air enters the intake pipe, it mixes with gasoline to form a combustible mixture, which then burns to generate power. It connects to the air filter on the top and the engine block on the bottom, and is often referred to as the throat of the car engine. There are three main reasons why the throttle body becomes dirty: The air filter cannot completely filter out dust from the intake air, and the remaining dust enters the engine through the throttle body. The high airflow speed at the edges of the throttle valve plate generates static electricity due to air friction, which attracts and accumulates dust. The intake pipe of the crankcase ventilation system is connected in front of the throttle body. After the engine is turned off, oil vapor from the crankcase flows back through the pipe to the throttle body. When it encounters low temperatures, it condenses into oil droplets that adhere to the throttle body and valve plate, which also attract a large amount of dust. During engine operation, the late closing of the intake valve causes some of the mixture and exhaust gases to enter the intake manifold, which then flows back and contaminates the back of the throttle body. After the throttle body becomes dirty, the following symptoms may appear: unstable engine idle, persistently high engine RPM, difficulty starting the engine, especially cold starts; unstable or no idle; difficulty starting the engine; insufficient engine power, poor acceleration performance, and unstable operation; black smoke from the car's exhaust pipe and increased fuel consumption. Throttle body cleaning cycle: Generally, it is recommended to clean the throttle body every 20,000 kilometers. If the vehicle is used in an area with poor environmental quality and high levels of dust particles in the air, it is advisable to clean it 1,000 kilometers earlier. Avoid frequent cleaning of the throttle body, as excessive cleaning may cause damage to it.
While studying engine construction recently, I discovered that the throttle valve is like the throat of an engine. It connects the accelerator pedal to the intake manifold. When you press the accelerator, you're essentially controlling the opening angle of the throttle valve's blade. The wider it opens, the more air enters the cylinders, prompting the ECU to increase fuel injection accordingly, which naturally raises the engine speed. This delicate mechanical structure directly determines the vehicle's power response speed. If the throttle valve gets stuck or has severe carbon buildup, you'll noticeably feel sluggish acceleration. It's also related to gear shift jerks in automatic transmission vehicles, so it's best to inspect and clean it every 20,000 kilometers. Electronic throttle valves also work with sensors to adjust the air-fuel ratio in real-time, directly affecting fuel consumption performance.
