The idle speed of Valin car suddenly increased, and the foot throttle didn't respond.

There may be the following reasons for the sudden increase of idle speed without stepping on the accelerator while driving:

1, automatic transmission will automatically downshift. When the automatic transmission car is in D gear, its computer program sets the upshift program. After the downshift operation, in order to maintain speed consistency, the idle speed naturally rises, which is a normal phenomenon;

2. It's normal that the speed becomes faster when the car is manually blocked downhill, and the movement of the car body is transmitted to the engine of the car, which restricts the increase of engine speed;

3. When the clutch is disengaged, the idle speed of the car will be improved to varying degrees, and when the air conditioner is turned on, the idle speed will be slightly improved, which is normal;

4. Do not rule out the reasons such as automobile failure, such as dirty throttle, excessive carbon deposition, gearbox failure or poor oil. If this is an abnormal reason, you need to go to a professional garage for inspection and maintenance.