Q: Rough Idle, Loss of Power, Stalling

asked by on December 07, 2016

Hello, so about a week ago my check engine light came on, then my car started idling very rough first start of the day & will stall if I don't rev the engine for a considerable time and let it warm. After warming, there's still idling issues at lights and loss of power, but it doesn't stall instantly.

My initial thoughts were plugs, coils, or the ICV. Looking for an opinion on it before ordering an inspection/replacement on here please.

Thank you for your time & help!

My car has 159000 miles.
My car has an automatic transmission.

Idle Control Valve Replacement $146.15 - $920.51 Get a Quote

This may be a result of 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 making the transition from a higher RPM back down to idle speed. 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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