What are the symptoms of throttle damage?

Symptoms of throttle damage are as follows: 1, engine idle speed is unstable or no idle speed: engine idle speed is unstable, high idle speed drops discontinuously, and it is difficult to start the engine, especially cold start. 2. Insufficient power: it is difficult to start the engine. When starting, the engine has insufficient power, poor acceleration performance and unstable operation. 3. The exhaust pipe emits black smoke: the exhaust pipe of the car emits black smoke, which increases fuel consumption. Throttle is a controllable valve that controls air to enter the engine. After the air enters the intake pipe, it will be mixed with gasoline to form a combustible mixture, and the combustion is successful. It is called the throat of an automobile engine.