Car stalls out when coming to a stop or driving and won't restart

What is your question?

JAG X-TYPE 2003 MODEL My problem has happened over a two year period where the Jag x-type suddenly stalls out when driving when coming to a stop or slowing down and won't restart Also has not started once when engine was cold. This has happened in both warm and cold weather. It happens intermittently and will not repeat when tested by mechanics and leaves me stranded on the road mostly.

What makes this problem better or worse?

There is no difference when engine is cold or hot

How long has your 2003 Jaguar X-Type had this problem?

Over a two year period