96 s-10 with a 4.3 vortec 2 wheel drive. With truck running down road all of a sudden engine cuts out and shuts off, no power. Turn off ignition and turn it back on, engine starts and runs for a mile or so, shuts off again. Repeat, turn off and turn on. This can happen all day long. Not sure if ignition is shutting off or fuel.
Try changing out your fuel pump relay with the horn relay and confirm its functionality. Its possble that a bad relay can be causing your problem. Otherwise test the ffunctionality of the ignition spark.