The car in question is a 1993 240 wagon.

Even on the coldest of days (-20F) in the winter the car does not idle high, just the same low idle speed as in the warm weather. If I give it some gas and rev it up a bit sometimes (rarely) it will stay at a higher idle speed for 10 seconds before dropping down to the usual idle speed.

Something I have also noticed is that it runs very rich at startup in cold weather, as if it's getting the extra fuel for a high idle but not the extra air. If I start it without depressing the accelerator it sputters along belching out rich exhaust for a long time and will even flood and die (then I have to wait awhile before restarting it) but if I rev it for just a few seconds then the mixture leans out and stays good after that.

It does have a new idle air controller, is that where the air for a high idle should come from?

The throttle body was recently cleaned, made it idle very nicely in warm weather.

It also has a new block temp sensor and the computer is getting the proper signal from it.

Any ideas?

Thanks!