914 rough idle until warm-- any ideas?
 

I have a 76 2.0 liter 9144 with an idle problem. When I first start it the engine idles at 1,000 rpm perfectly. Then after about a minute it starts oscillating between 0 and 1000 until its warmed up, at which point it idles perfectly again. I've checked all my vacuum hoses and they seem secure. Any ideas of where to check next?

thanks,

brian

Check your AAR (Aux. Air Valve).
It's a controlled vacuum leak and is supposed to close slowly as the car warms up.

It sounds like yours is sticking. You can clean the inside (it's a slide-valve) using any kind of degreaser.

It grounds through the engine case, so make sure it's bolted down in a way to get good contact.

SmileWavy Andy