My 84' dodge 318 v8 will not shut off when I turnthe key so I put it in drive to kill it. Itkeeps turning over very rough for a few seconds then puffs out. I not sure if it hasto much compression from the previous overhaul/preowner. Or is it ignition module or any ignition.Any suggestions?

Thanks.

P.S. I will try it all and will post results.

 

The ignition lock cylinder is bad most likely, start there.

 

Could be a totally different thing too so keep your mind open, the Cadillac i am working on does the same thing sometimes. I still have to figure that on out but start at the ignition lock cylinder if thats acting weird such as not locking into certain positions.

 

Try higher octane fuel sounds like a preignition problem.