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Q: High idle

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When you start it on a cold start it idles as it should but as soon as it idles down motor is warm and you touch the gas pedal idle goes up to 1500 rpms and stays there I took the air intake off and there is a lot of fuel going into throttle body I changed coolant temp sensor that didn't fix it

My car has 190000 miles.
My car has a manual transmission.

Hi there, This may be a sign of a failing idle air control valve. The idle air control valve is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is controlled by the vehicle’s computer which 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. However, when the engine RPM drops below the normal range of 800 RPM (for most cars), it is more than likely that you are dealing with an IAC valve problem. In cases where this valve is clogged or is failing, your vehicle will stall instead of slowing to an idle after the release of the throttle. I would recommend having an expert from Your Mechanic come to your home to replace your idle air control valve.

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