95 XJ6VP Shuts Off Idling

A few times lately, after starting from cold, my 95 XJ6 will start and idle perfectly BUT will suddenly cut off as if I turned the switch off. It might idle for a few minutes before it will off. It restarts instantly and continues to idle perfectly for days until it does the same cutting off. Any ideas what is going on???

Richard
95 XJ6 VP
97 XJ6 VP