Passat throttle fault performance

Throttle fault performance is as follows: 1, the engine idle speed is unstable, the high idle speed continues to drop, and the engine is difficult to start, especially 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.