When the engine is hot it wants to start but won't on 1996 Chevrolet 1500 Pickup

I have a 96 with 201000 miles. If the weather is in the 100's and I've driven 20 to 30 miles it won't start when I return to it. It wants to start but dies with the sound of vacuum air escaping. If I lift the hood and let the engine cool down in about 15 to 20 minutes it will start but run ruff for a few seconds. I have had the catalytic converter tested and its good. I have had the fuel filter and pump changed but it still happens. I am open for suggestions.

Asked by for the 1996 Chevrolet 1500 Pickup
it sounds like it could be an ign module when it wont start check for spark and fuel pressure