Jeep No Start update
The computer was again showing code 54 - no sync. This sensor is mounted inside the distributor. Since I had a spare distributor, I elected to change the whole unit instead of just the sensor.
Working in the parking lot between rain showers, I carefully marked the direction of the rotor for the old distributor. Installed the spare making sure the rotor ended up pointing at the mark I made so that it would be indexed the same as the old one.
I reconnected the wires and even with the low battery, it fired right up.
I am happy to have it going again. Maybe this will cure this very annoying intermittent problem I have had for a while.