A friend of mine had a stroke of genius. Install a small ball valve in the air line to the supplemental air valve (aka AAV), thus creating an infinitely variable orifice adjustment. Then, start the car cold with the valve open all the way and close it down until the idle hunting stops...is there any reason this wouldn't work?

I know it's just a work around for what could be a stuck supplemental air valve but it seems to be a, cheap, easy and elegant fix to a stubborn problem. It would also be really easy to adjust again in the future if the condition of the supplemental air valve changed.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz