Tractor Repair: Ford 5000 Diesel mysteriously quits running, ford 5000, vapor lock

Question
I have a Ford 5000, diesel. The tractor will start and run great for anywhere from 10-20 minutes, and then die like it is out of fuel. I have replaced the fuel filter and cleaned the tank as much as possible. seems to have ok flow. Any components that might be failing after tractor gets good and warm? Most of the time the tractor will re-start after a few minutes and run for 5-10 minutes before dying again. It seems to quit more quickly when the pto is running. Where do I start?

Answer
Two possible causes of your problem-1 ign coil going bad & breaking down with heat. 2-vapor lock caused by poor cooling possibly a hood design problem.Next time you run,when eng dies,have someone sit on tractor & crank eng,while the're cranking,check for spark,if you have spark,then problem in fuel system,if no spark,then ign problem on eng,there are 2 other possible elect problems on eng,but need mfg & mod# of eng to check