1995 ciera won't start
 

I have a 1995 oldsmobile ciera 3100 v6, I just replace the fuel pump/filter plug wires. My problem is the car will run for a hour or so then when I shut it off for half hour or more it wont start again. hour or 2 later it will fire up run great again till I shut it off. What could be my problem? Is this a bad Ignition Control Unit? or something else. It does this every time you drive it for a bit then turn it off.

Thanks