What are the symptoms of a faulty engine throttle?

[VonLeila]

Engine throttle malfunction symptoms: 1. Unstable engine idle speed, persistently high idle speed that doesn't drop, difficulty starting the engine, especially cold start difficulties; 2. Unstable engine idle speed or no idle speed; 3. Insufficient engine power, poor acceleration performance, unstable operation; 4. Black smoke from the car's exhaust pipe. Proper and standardized cleaning of the engine throttle can ensure normal engine operation, but cleaning must be moderate. Excessive cleaning can lead to premature throttle failure, as frequent cleaning gradually removes the special coating inside the throttle chamber. Without this coating, the chamber becomes more prone to oil buildup, which can cause the engine throttle to fail prematurely.