Sounds like it might be your MAFS "Mass Air Flow Sensor". Usually when they go bad. And you run the a/c it puts a strain on the motor and will cause it to run rough and die. But I could be wrong. I don't want to give bad advice. But that would be my first clue. Either that or you have a bad vacuum line somewhere. Such as a PCV valve. Don't ever look at the most expensive things. Always start cheap. Then if it doesn't fix it. Go to the more expensive things. Just a tip.
Hope I helped you out alittle.