If the "Check Engine" light is on, then you may be able to get some information from the error codes you can check. See the FAQ files about this, and remember, you have a Rex/Regina car, so look toward the end of the FAQ article for the Rex/Regina codes and don't use the Bosch LH 2.4 ones at the beginning of the listing. Check both the fuel computer and the ignition computer for codes.

The codes may help a lot, or they may be useless: The one-year-old, MTC, heater control valve in my 1991 Turbo SE just split completely in two and the car blew out all of its coolant in a matter of seconds (a pretty serious problem, I'd guess, and certainly a good reason to "Check the Engine"). Needless to say, it overheated before my wife could get pulled over and shut it off. The "Check Engine" light went on then, but would not go on after the tow truck got it home. There were no error codes set either.

When you cleaned the throttle body, did you set the throttle plate position properly, as described somewhere in the FAQ? It is a pain in the a$$, but the computer and IAC need the plate to be adjusted just right. Also, did you check whether or not the TPS was set right too?
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1955 Human, Scott; 1991 745 Turbo, Brunhilde; 1990 745GL, Snuggle Bunny