Cadillac Repair: 1982 Deville Fuel System Problem, throttle plate, vapor lock

Question
I live in AZ and with the summer heat the engine began to stall at stop lights.  I thought at first it was Vapor Lock but it seems to be getting worse.  I have to keep the RPM's high in order to keep it running and this does not work all the time.  I never have the problem in the morning when its cool out.  Most times car will start right back up.  Any advise would help a great deal.  Thanks.

Answer
VAPOR LOCK my BUTT !!!!!!!

The throttle body and both sides of the throttle plate inside the throttle body develop a blackish residue which causes the throttle plate not to close all the way. Clean these areas with carb cleaner aerosol can and or similar product.