Please help. My 93 cadillac deville cuts off while driving. It restarts once you put it in drive, but this is very dangerous. It cut off 3 times in less than 20 minutes while driving through town. Of course I'm scared to get on the expressway. What could be wrong? ... wiring?

Will a tune-up solve the problem? It has 97,000 miles on it. spark plugs, tps, oil and filter recently changed.