Subaru traditionally resets idle speed.

There is something wrong with the engine.

1. Poor ignition (such as cylinder line, spark plug, ignition coil).

2. The mixture is too rich or too lean (such as oxygen sensor signal, serious carbon deposition at the intake of the intake valve, etc.). ).

3. Throttle and idle motor have serious carbon deposits or are damaged.

4. The fuel injector is stuck or damaged.

5. Air intake system leaks.

6. Poor exhaust (e.g. blocked three-way catalyst).

7. The engine timing system is misplaced or adjusted inaccurately.

The most common cause of automobile jitter is that the throttle valve is too dirty or the fuel injector has too much carbon deposit.

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 leads to the lean mixture during cold start and makes it difficult to start. In this case, only when the gasoline adsorbed by carbon deposits is saturated, it is easy to run into the car. After running into the car, the gasoline adsorbed on carbon deposits will be sucked into the cylinder by the vacuum suction of the engine for combustion, which will thicken the mixture and dilute the combustible mixture of the engine, resulting in idling jitter after cold start. The lower the temperature, the more oil is needed for cold start, and the existence of carbon deposit will affect the smooth start.