coil blowing up

i think something wrong with my car. My engine will just shut off at highway speeds without any warning. Everytime i replace the coil, it will work again for about a week. Other times the car will just sputter and die and shot smoke out the intake. Any help about what is wrong.

No help, nobody has had this problem? It is kicking mine and the other techs ass's at work.

Ive had this problem!! I dont really have an answer though. What I did was went to the junkyard and bought a whole new dizzy. Its been working for more than a month now, so I hope it never happens again. Goodluck though.