Thanks for the reply Aleekat,

Yes, I read earlier about the ICV. They are unbelievably expensive. $200+ for such a small thing. I will try to find the FAQ and hopefully with cleaning it might fix the high idling.

The throttle position sensor seems to be correct. I can hear a clear clicking when closing the throttle. Or is there another way to determine if it is adjusted correctly?

I don't think it would be a vacuum leak as that would not cause only the occasional stalling of the engine. Or am I wrong on that part? The engine runs fine. No missing or knocking. Lots of power. (except for the occasional stalling)

A bad harness would be bad news. When I was working on the car a couple of weeks ago I thought it might be a bad electrical connection somewhere and with the engine running I wiggled any electrical connection I could see and nothing happened. Do you or anyone reading this have experience with a bad electrical harness? Would you make a educated guess what part of the harness or electrical connection would be most prone to breaking down and causing this stalling behavior?

I read in one of the post about bad fuse connections. It was about a different model and year of car but I was wondering could that be the problem on this car also? Does this car have only the one fusebox behind the ashtray? Or are there others that i need to check?
Thanks again for your reply. Much appreciate all the help you and others give to help us keep our volvo cars running.
Merry Christmas