1997 Grand Prix will just stop running. It has happened at 60 mph and at 20 mph. After pulling off the road the car will start right up again. There is no warning it will happen. Mechanic is unable to find problem. Any ideas ???
The mechanic isn’t going to find the problem unless the problem is occuring while he’s looking at it.
There are two things that can cause this type of problem. And these are either the crankshaft position sensor is defective, or the ignition module is defective. If either of these cut out, the engine will stop running as if the ignition were turned off.
That’s why it’s so hard to diagnose an intermintant problem. You don’t know what component to replace, unless the problem occurs while diagnosing. Otherwise, everything looks fine!