Misfire/stall Fiat 124 Spider

Shortly after gassing up and cruising at about 70 mph, my Fiat 124 Spider misfired, backfired and stalled out.  When that has happened in the past it has been because of an over-heated ignition coil.  I carry an extra and when I have replaced it, the car starts immediately and runs well.  This time, not.  Had to get a tow home.  The car will start and run for a few moments, misfire, with the tach jumping, and stall and refuse to start for some time.  The battery charge indicator does not come on when the key is on, however, the battery seems to be holding a good charge.  I've used dry-gas just to make sure the recent fill-up wasn't at fault and have put in a new coil.  Any suggested diagnoses would be appreciated.