car is missing after it warms up, but no engine lights.

What is your question?

I have a 1993 seville sts, I have been trying to find out why its missing and running rough. when its cold and not warmed up its fine, but then starts to act up more and more. I have no engine lights on and cants find any codes in the system. I have new plugs, wires, fuel pump, TPS, air filter, fuel filter, ecm and still nothing. all my grounds are good and free of rust. I tried a suggested test to check the coil packs, (remove the two wires from each one and see if they arc to each other) I dont know if thats a legit way to test them, but Im out of ideas, please please help, its not running HORRIBLE, but almost like its missing one or two cyl MAX....