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Q: Car stalling

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Hi My car will sometimes stall when shifting from reverse to drive. Sometimes needs longer than normal cranking time to start. The ideal rpm seem to fluxuate when the engine gets warm. The spark plugs and wires are new and the mass air flow sensor has been cleaned. A code reader shows no unusual codes. Please help.

My car has 62000 miles.
My car has an automatic transmission.

A: You may have a dirty or failing idle air co...

You may have a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. Since this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

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