The cold car began to shake violently.

First, there are several main reasons for the start-up jitter of the cold car: carbon deposition, weak ignition, low cylinder pressure, unqualified fuel and so on.

More detailed reasons are as follows:

1: There are too many carbon deposits in the throttle, injector and air intake, which may be one or all of them.

2. When there is too much carbon deposit in the engine, the gasoline sprayed by the fuel injection head will be absorbed by the carbon deposit during cold start, which will lead to too thin mixture during cold start and make the start shake.

3. Mechanical faults such as ignition coil, spark plug and fuel injector lead to cylinder missing.

4. Low oil pressure or cylinder pressure leads to insufficient power.

5: The fuel quality is unqualified.

6: Idle speed control valve is damaged or too dirty.

7: Air leakage in the intake manifold.

8: The engine arm or gripper pad is damaged, etc.

9. The oxidation or low grade of engine oil is mainly due to poor fluidity at low temperature and inadequate cold start protection of the engine.

Two: it is recommended to go to a 4S shop or a repair shop, and go in for inspection and maintenance to improve the safety of the car!