The idle speed of the cold car is unstable. Is the high and low heat normal?

The idle speed of the cold car is unstable, and it is abnormal to go up and down. The reason of unstable normal idle speed or starting idle speed is often understood as the influence of carbon deposition. It is undeniable that carbon deposition does affect the idling stability, but the vibration of * * * is often in a regular or relatively regular state, and there will be no large fluctuation of speed.

Brief introduction of causes

Too much carbon deposit on the throttle valve, too much carbon deposit on the throttle valve and the surrounding air intake, and the change of the cross-sectional area of the air passage make it impossible for the control unit to accurately control the idle intake, which also leads to the mixture being too rich or too thin, resulting in the unstable idle speed of the car.

Fuel system failure, fuel injector blockage, fuel filter blockage, fuel pump filter blockage, fuel pressure regulator failure, fuel return pipe blockage and other failures. Will lead to incorrect fuel injection, resulting in too rich or too thin mixture, leading to unstable idle speed of the car.

Failure of ignition module, incorrect gap of spark plug, ablation or damage of spark plug electrode, excessive resistance of high voltage line and other faults lead to the reduction of ignition spark energy or fire, which leads to unstable idle speed of the car. If the idle speed of the car is unstable, we should deal with it as soon as possible. We should know that the engine is not at the ideal idle speed at that time, and the fuel consumption economy and environmental protection will become worse.