Hot Starting Problem

Just started driving the 300 there again and realised it has developed a hot starting problem where it starts fine first thing in the morning but if I drive it up to temperature and turn it off it wont start again. It turns over but just wont start like there is no diesel and if it does start its mad lumpy like it only ruinning on 3 cylinders. I learned this the hard way by being stranded at the shop on saturday morning for 2 hours so any help would be greatly appricated

Thanks