When I run my diesel truck (its a standard transmission) for a while and turn it off it won't restart until it is completely cooled off.
starting on 1992 Chevrolet 2500 Pickup
When your truck is completely cooled off, you are using the glow plugs, so I would start with the basics, i.e do a compression test, for which you will need a special compression testing kit. then check your injector timing to make sure that you are getting fuel at the precise time, I have found that injector timing is a mission critical spec for a diesel. How many miles are on this motor?
I have a 92 6.5 turbo that did the same thing. If it is a stock injector pump they have metal diaph in them that warps when hot after time. Mine also had excess smoke when starting cold because of fuel leaking through the pump when it sat for a couple days. Had to replace the injector pump..A diesel tech from a site from N York told me to place a cloth around the pump and pour ice water on the pump to cool it to confirm that this was the problem???? It worked but, I didn't like the idea of putting cold water on a hot engine.They have newer design pumps now that eliminates this problem