99 Disco 2 wont start when hot
 

Hello. I own a 1999 Land rover Discovery II with 218000 miles. Mechanically it runs fine. Last summer, on 5-6 occasions (mostly on a hot day) after starting the vehicle in the morning and driving it regularly and then parking, it would not restart. In fact, it would not even crank or turn over. Totally dead. I had AAA check battery and alternator and no issues. It was towed to a local foreign car mechanic who changed the starter.. A few days later same problem. It obviously wasn't the starter and the fuel pump is relativelynew. After allowing vehicle to cool down and as the day got cooler would start right up. Happened about 5 times. Took it to another mechanic who couldn't find the problem. Finally, I broke down and took it to a local dealer. They seemed stumped as well. At this point I took vehicle home and throughout winter( 5 months so far) no issues. Some forums indicate crank sensor issues, xyz switch etc., but these problems seem to involve vehicles which at least crank/turn over. Mine nothing totally dead. Any suggestions.