Stalled and I can't get up

[addotta]

Hello everyone,
It's been a while since I've been here..i really like the new look.
Everything with my Xj has been great for the last year .everything up until now.
i pulled a real bonehead move the other night....decided to take her to the carwash in single digit weather, I left the engine running while doing so thinking that nothing would get hurt...when the water finally stopped so did the XJ...no big deal...thought that maybe the distributor got wet..not so.I could not get her restarted ..had to call AAA...it's a sad day when you have to watch your jeep get hauled onto the flatbed...finally started back up in the morning...
Then I was on my way to work the next day thinking everything was great...cruising at around 65 slowed down to make my
turn... then nothing...She stalled out on me again and I couldn't get her started again...wound up killing the battery and calling AAA again to take it to a local garage...
They called me back to day and couldn't find anything wrong with it. Said that they drove it up the same hill I was driving whrn it happened at 75 mph and nothing happened...
got a new battery though. Can someone please try to explain what could have happened here?

Thanks,
Tony

88 XJ Laredo
4.0L 6cyl
Ravin Exhaust
180 deg thermostat
FIPK
MSD Coil
Magnecor Wires
235,000 miles