1990 fox pls help

I have a 1990 fox, it runs great, but, in the summer mostly and sometimes in the winter if i leave it idleing for a while the coolant temp stays normal but it seems to get what i think is a vapor lock situation. It will stall, wont start up until i open the hood and let it cool down for about 10 mins. In the summer it does it just sitting shortly at like a drive through, in the winter it will do it if i let it idle for about 25min??? (veedubmikey@yahoo.com)