What are the symptoms of Fox's broken throttle?

The symptoms of broken throttle are: 1, the engine idling is unstable, and it is difficult to start the engine, especially the cold start; 2, the engine idle speed instability or no idle speed; 3. The engine is difficult to start; 4. Insufficient engine power, poor acceleration performance and unstable operation; 5. The exhaust pipe of the car emits black smoke, which increases fuel consumption.