98 Buick Regal intermitantly stops dead in the road. It restarts and may not stop for days and then dies. That’s dangerous on the highway.
Good mechanic has had it for a week. Can’t figure it out. HEPL!
Short duration intermittent trouble can be real difficult to find at times. The trouble is most likely due to something going wrong electrically, possibly in the ignition area or fuel delivery system. If the trouble occurs well after the engine has heated up then the trouble may be heat related. I would look into the ignition system as a possible source of trouble along with the ignition switch. The fuel pump relay is another potential problem. To help try and flush out the trouble I would use a screwdriver handle to tap on suspected trouble areas and see what happens. The fuse panels are another area to check.
Any other clues you can provide, like certain warning lights being on or other accessories not working when the trouble occurs can be a real help to solve the riddle.
Edit: Main power relays are another thing to check also.
Here’s an interesting article on this exact problem.
http://www.babcox.com/editorial/us/us80826.htm
Tester