I got a 91 1st gen cummins. i was backing outta my driveway last night and it shut down in the middle of the road and smoke come out of ignition and under the hood. so i pulled it back in the driveway and messed with it. if you hit the side of the steering colummn it'll start. any ideas y it did this ???

 

Ignition switch or more likely pinched wire., You will have to pull the covers and start looking. I believe 91 was the first year of the removable cover steering column?