About to get rid of my 1997 Grand Prix SE..3.8 V6. Reason..a problem that NONE of the local GM dealers or several independent shops can solve. The problem: the car will ride very smoothly..no hesitations...idles smoothly and quietly. Then several times a month it just STOPS/CUTS OUT. It will crank and try to turn over...after about 3 minutes the car starts. The GM dealer has had the car in shop for 8 days, hooked up the their diagonistic machines and no codes ever appear. Of course when they drove it, it didn't stop. Any ideas of how I can HELP THE MECHANICS help ME solve the problem. I simply CANNOT keep a car that can stop at anytime in anyplace, need a more reliable car. I have invested several thousand dollars in this good looking black car of only 88 K. Any ideas?