1996 probe GT V6 no spark after car sits in sun

[billho]

Here is my problem.

My car starts fine when its cool outside but after it sits in the sun for a while it won't start and there is no spark.

I can move the car into the shade open the hood point a fan at the engine and run it for 10 to 20 min and the spark returns the car then starts.

I have allready changed the distributer twice.

Can some one help me with this one?

Thanks