Sounds like the ignition switch harness ( it is on the right side of the steering clolumn if yopu take off that plastic collar right behind the steering wheel.) My 89 would do thta if I took a turn, it would stall out and then start back up and stall out and start again and be fine. I just, just put zip ties on mine and never had a problem with it after that. I know it sounds kind of ghetto but it worked and no one ever knew.
Drew