WHY does a 1994 Ford Thunderbird LX V6 3.8L not start after it has been running for a while? Example: drive to store, come back after 20 minutes and car will not start. Sit there for about 20+, then car finally starts. Put on diagnostic test = only need distributor (replaced and still doing the same thing)

Fuel pressure regulator might be the problem, the diaphram ruptures and the regulator leaks gas into intake, causing the engine to flood. Try holding the gas pedal to the floor while your cranking it. An easy way to tell is pull the vacuum line off the fuel pressure regulator if it's wet with gas or smells like gas that's the problem. It should be on the fuel rail, on top of the engine and looks like vacuum advance unit only smaller.

Sounds like your ignition module is bad. Its located on the passenger side inner fender mounted to an aluminum heat sink. You can take it to an auto parts store and get it tested for free. When they get hot, the car will not start. When it cools off, it will run fine. Eventually what may happen is the car will die while driving. Net time this happens, put your hand NEAR it but not touch it. Should be really hot. Using a damp rag, you may be able to cool it off and start it faster. Eventually, it will need to be replaced. 1 other thing, is you have a ick up inside the distributor. Since you repalced the dist. then this should already have been replaced. When replacing the ignition module, make sure you get the grease for it.