Hi Jacob, thanks for the helpful advise. I have a scanner and the codes are P1632, P1638, & P1638. The car sat overnight (~20 hours) and I turn the ignition to ON but did not start it. I read the codes above and shut the car off. I looked up the code on OBDCodes.com and it appears to be:
P1632     Throttle Valve Adaptation; Adaptation Condition Not Met
P1638     Throttle Valve Position Control; Throttle Stuck Temporarily
P1639     Throttle Valve Position Control; Throttle Stuck Permanently

When I went to read the codes a second time, the EML light was out and I took the opportunity to start the car. The car idled normally and the EML stayed NOT lit for 30-40 seconds. The throttle was very responsive and the quickly move the car from the street to the garage before the problem started again. Th SES light is still on the the 3 codes above are still being sent from the OBD system.

What do you suggest from here? (the coolant problem is really a separate issue)

Thanks
Michael

Thanks Jacob, I disassembled and removed the throttle and didn't see anything obvious that was an issue.   I removed and cleaned all the plugs and coils, then restarted the car. It "purrs" and the SES light is no longer illuminated. I test drove it and I could not get it to stall/hesitate. Hopefully rebuilding the throttle fixed what ever was causing the issue.

On the overheating side, I inspected the fan clutch and, wearing a thick leather glove, while the engine was at idle, I was able to stop the fan with little effort. I had a helper slowly increase the engine speed and did not feel and increased resistance and/or load on my hand, holding the fan. I think I need a new fan clutch and while I'm at it, I'll replace the 2 belts, the inside ribs have some cracks.

Thanks for your help and I'll "accept" this evening.

Michael