91 lincoln stalls in Hot Weather/ac on-150 miles

I am having a 1991 lincoln town car issue:Car has 95,000 miles and normally runs and starts perfectly-In very hot weather(85 degrees and up), with the a/c on, after 125 miles or so, car will start stalling out and die-my correction only to get going is open hood, let engine cool for at least 15-20 minutes, after which it will start right up and run fine for a peroid of time varying from 20 minutes to 45 minutes then repeat the cycle-It is a highway business car with all the oil changes-I am a 76 year old driver and need quality advice for a reliable car-Thank you

These cars have a problem with the ignition module that sounds just like this. I’d have this checked first.

I think BK above has it right. A heat-sensitive component in the ignition system is failing when hot. Eventually it will fail altogether, but why wait?

Lots of Fords of a certain vintage had this problem and yours may be among them.