What happens when the car engine idles up and down?

What happens when the car engine idles up and down?

1, spark plug and ignition coil are two very important components. If there is something wrong with one of these two parts, it may cause the idle speed of the car to rise and fall. If problems are found in these two places, the solution is simple, just replace them as required.

2. The throttle valve has too much carbon deposit. If there is too much carbon deposit in the throttle, it will lead to a series of problems such as the decrease of engine intake, the increase of intake resistance and the extension of intake time. When these problems occur, the mixture will be too rich or too lean. The solution is also simple, that is, just clean the throttle directly.

3. Air leakage occurred in the intake system of the engine, which was caused by dilution of mixed gas. This is because the air that should not have entered the cylinder also participated in the combustion.

4. The fuel nozzle is blocked, or the fuel atomization effect is poor. When the fuel nozzle is blocked, there is no fuel in it, and it is all air, so a new mixture cannot be formed.

5. If the three-way catalytic converter is damaged or blocked, it may also cause the car to rise and fall when idling.