What are the symptoms of Volkswagen Bora's broken throttle?

What are the symptoms of "Volkswagen Bora's accelerator is broken"? Introduce the following related contents:

Volkswagen Bora's accelerator is broken and has the following symptoms:

1, the idle speed of the vehicle is shaking, it is not easy to strike a fire in cold weather, and the indicator of the tachometer is unstable (idle speed is unstable);

2. Reason: Oil vapor is the main reason. When the engine is running normally, there is bound to be crankcase exhaust gas, especially when using low-grade engine oil. In a particular design, one of the crankcase exhaust systems is connected to the front of the throttle.

3. It is very likely that a part of the hot crankcase exhaust gas will return to the front of the throttle through the small hole. When idling, this hot crankcase exhaust gas will gradually cool with the air intake, and finally the temperature will be so low that an oil film will be deposited near the throttle. This oil film will further absorb dust and play a decisive role in adding fuel to the fire;

4. On the other hand, another part of the crankcase exhaust system is connected with the throttle valve, and this part of exhaust gas will directly pollute all vacuum tubes, including the fuel regulator.