i did adjust the timing with the vacuum line off of the distributor like you suggested and got the engine timed to about 10 degrees BTDC. I then compared the advance with the vacuum line connected. the distributor advanced the timing past 10 degrees BTDC but so far it isn't repeating it's poor idle behavior from yesterday. I'll have to hunt for a new air cleaner with the IAT sensor. i did make sure the connectors on the temp sensors were clean and tightly connected. i'll give it a test drive again and see if it's gotten better or i've got more work to do