Open AAR and low idle first 2 min
 

What could cause this?

I know my AAR opens almost fully in cold weather, but the idle on my car stayed low around 900 for 2 full minutes before jumping to about 1800. After that, I could see the AAR's closing affect the idle speed as I drove home.

The car starts right away and idles smoothly even at the lower speed.

It is a closed loop K-Jetronic (82 SC), and I am just wondering what component or combination of components, temp switches, time switches, etc. could hold the idle down for 2 minutes while the passage through the AAR is almost completely open.

Olivier