No spark when hot.

My car start and run as normal. But after i drive for a couple minutes and the engine getting hot.  RPM goes to 0 and
the engine turned off by itself.  I tried again but it won't start. I checked and there is no spark.  But after 30 minutes
or when the engine cool down, it does have spark and the car seen like normal.  I changed a new distributor, cap,
rotor, spark plugs and wires but still have the same problem. Anyone know what the problem is???