Why does the Mondeo's idle speed fluctuate when the air conditioning is on?

1 Answers
Samuel
07/30/25 8:44am
The reason is that the idle air orifice is blocked, the idle device is not working properly, the spark of individual cylinder spark plugs is too weak, the sealing of individual valves is not tight, the intake manifold is leaking, the ignition timing is too early or too late, or the idle speed adjustment is improper, which leads to the fluctuation of idle speed. Here are the specific details: 1. Dealing with unstable car idle speed: The most direct method is to adjust the idle speed by adjusting the throttle opening adjustment screw so that the engine runs at the lowest stable speed. 2. Car inspection: Since a series of inspections need to be carried out on the car before adjusting the idle speed, such as engine temperature, valve clearance, ignition system condition, pipeline sealing, choke opening, throttle sealing, etc., it is not recommended for the owner to operate. It is best to go to a professional repair shop or 4S shop for adjustment.
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