1993 Jeep YJ Ignition coil

I have had the jeep for 14years and have never had a problem with the Ignition coil. I changed the oil with syn. 10/40 getting ready for a long trip. I let a friend use the jeep to start his truck after installing a rebuilt motor that night before leaving. The day after on the way to the store it started to hesatate on take off. I got it home and it would not start after turning it off. I found it had no spark to the spark plugs but had power to the coil. I replaced the coil and it started up. I left to go on the trip but only made it 105 miles before the jeep died. After having it towed home, found same issue. I replaced the coil again and it started up again. I still am having this issue, I keep 2 coils and when one fails I change it out and replace the failed one. What could cause this? I know he jumped it with pos. On the battery and the Neg. On the frame. Is this now a PCM issue? I get Battery Volts to coil wire, should I? Please help with info. Thanks.