I had issues with my F134 in my 53 CJ3B: It would die and start back up, and run for hours or minutes, and start right back up again.
It finally refused to start at all. On a list somewhere about this problem, someone suggested checking the ignition switch. I disconnected the wire from the switch to the coil, and did a jumper between the battery and the coil - started right up and ran!
I replaced the ignition switch and it has run fine ever since.
(I still carry the jumper in the toolbox)