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Q: Jerking forward at a full stop.

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My vehicle have a forward jerking sensation when i take my foot off the brakes at a stop or coasting forward not under load. As soon as i accelerate the jerking goes away. What might be causing this?

My car has 63000 miles.
My car has an automatic transmission.

A: This may be related to a dirty or failing i...

This may be related to 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. As 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. In your case the idle air control valve may be misreading the load and relaying that it needs more fuel to the computer which then supplies more fuel than needed resulting in the forward lurching reaction. 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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