Confused and Frustrated

I have a 1987 Mercury Cougar with a 3.8 V6. Just the other day the car up and died on me. My Dad and I narrowed it down to no spark. every now and then it will start and run for a few minutes then die and not start back up. We changed the Ignition coil and the module on the distributor and it still does the same thing. Does anyone know why this is happening and what else I can do to fix it. Please Help Thanks.:banghead:

Take a test light and put it on the negative coil. Have somebody try and start the car it should blink. If it don't blink the pickup is bad in the distributor.
It takes a special puller to change. You can buy a rebuilt distributor.
Make sure you mark the rotor to the distributor and transfer the mark so it will start when done.
Otherwise check the computer ground and the relays.