Car shuts off while running!!!

[PKRWUD]

The neutral saftey switch can prevent starting, but can't kill a running engine. I believe it's a problem with the battery cables and/or alternator output connections. The backfire confirms this wasn't fuel related, and that the ignition was shut off. The backfire was caused by the fuel that was still being pulled into the engine that didn't ignite because the ignition killed. Normally, a bad battery connection wouldn't kill the engine if the alternator was in good working order, but the fact that the subsequent attempt to start the engine resulted in a weak battery condition tells me the alternator may not be up to par, and was unable to support the load when the battery connection was lost. I would first inspect and clean the battery terminals and cables, and verify they are on tight. Next, I would check the alternator output at idle and at 2000 rpms, both with and without a load.

The person who is having the problem with the neutral start switch needs to replace it. They're cheap, and should never be simply removed and forgotten about. Even the best of us have accidentally tried to start a car in gear, and that can be dangerous if the switch isn't there to prevent it.

Take care,
-Chris