Big Problem with talbot express 2.5 diesel pilote (non turbo)?

Hello, I am trying to find some information for my Father. He brought this camper and he had a few trips out in and that was fine. Then he was going on holiday and it started to cut out. The symptoms seemed to be that it eventually overheated. He had it looked at and was told the cylinder head was cracked so he spent a fortune having the engine rebuilt, reconditioned fuel pump etc. Once back together the engine runs perfect but once the engine gets hot and is stopped it will not restart. Fuel is not getting through to the injectors. This also does this when driving, simply cutting out. Does anyone have any ideas why this is? Simply put when the engine gets hot it cuts the fuel flow of to the engine. Any help would be great!!