Car wont restart after sitting for 5min ???

Problem: car initially starts and runs fine, however when it sits ((errands)) even for 5 min it wont turn back on: crank , crank ,crank?? Could this be related to the carburetor? Heat? Rich/lean? Or?
Has anyone experienced this or have some insight.

I had a warm start problem with electronic ignition.... Check the distributor reluctor gap to the pick-up and make sure it's .007" - .008" with a non-metallic feeler gauge... I have found them too wide, even on new ones, so don't assume the gap is correct even on a new one...