[ohecht]

I've followed all the CIS and idle threads with great interest (especially the ones regarding replacing CIS with an EFI system) over the year(s), since my idle fluctuates during the winter occasionally, but today I think I noticed a totally new symptom.

The strange part is that it happens when the car is already at operating temperature, but only during the first few minutes after a warm start.

What happens is that the idle dips down below its stable 900 RPM point for about 10 seconds, and then back to normal for 10 seconds, etc. The cycles last much longer than the typical idle swings during warmup, which I plan to address tomorrow using John Walker's advice from yesterday regarding a possible rich condition.

The fact that it happens when the engine is already warm, but only during the first few minutes after a start, and the slower cycles makes me wonder what component it could be.

I know the AAR and WUR operate when the engine is below operating temperature, and the AAV operates for the first second of startup, but what component can affect idle speed in such a manner when the engine is already above operating temperature but only for a minute or two after startup?

Olivier