I have a 1994 Pontiac Bonneville, V6, and 3.8L. A few months ago around 10am, I was out driving locally. 30 to 40mins later the car stopped. There was no warning lights, no sound from the engine, and all of the interior lights, etc turned off. It just stopped. While waiting for a tow truck which would took 45mins to an hour, 30 minutes into waiting, the car started and I drove it home.
I have replaced the - Ignition Coil/Module, E/Fuel Pump, Fuel Filter, Crankshaft . Position Sensor, Fuel Pump Relay, Oil and Oil Filter, Computer, Valve Cover Gasket, Battery, Sender/Transmissor, Alternator Connector (it was cracked), Alternator. I changed the Spark Plugs and Wires. I added Injector Cleaner and had a diagnostic check. There were no problems found. I replaced two to three items at a time during the months after it stopped running. Two weeks ago, I was using a 12V power inflator for the back tire, when I plugged it into the back seat cigarette lighter, with the car running. Within 5mins the car stopped running and it did not start up again for two weeks. After changing the starter it will run for about an hour and stop. After 30 to 40 min it would start-up again. Can anyone help me?

The problem is more then likely a battery cable. You need to remove the connections on both ends of both cables and clean them good. This should fix your problem.

So the bad battery cables caused his car to die whilst he was driving it?

It is common for bad connections to the battery to cause this type of issue, it is also common in your year for the ECM or computer to cause this issue.

Beginning of the summer I diagnosed a 94 with nearly the same symptons. When all else fails...it'* usually the ecm. Unfortuantely there is no way to know until you swap your eprom (chip) into the new pcm and fire it up. One other point of interest is that local parts stores here have the ecm stocked on the shelf and it was only used in 94 and 95. This says to me it'* a pretty common part to be stocked.