The key cylinder is attahced to a small rack and pinion (like a microscope). From the rack there is a rod going down the length of the steering column to the actual ignition switch. The switch is attached to the base of the steering column on the topside that is hardest to see. 
The adjustmant is made by loosening the screws holding it to the column and moving the switch, then re-tightening the screws.
There should be a good explanation of the adjustmant procedure in the Chilton's.
To confirm it's an adjustmant issue, try turing the key back to acc the next time it won't shut off. If going to acc shuts it off the switch needs to move up towards the steering wheel a bit.
Rene
The adjustmant is made by loosening the screws holding it to the column and moving the switch, then re-tightening the screws.
There should be a good explanation of the adjustmant procedure in the Chilton's.
To confirm it's an adjustmant issue, try turing the key back to acc the next time it won't shut off. If going to acc shuts it off the switch needs to move up towards the steering wheel a bit.
Rene
