vw lt 35 2.8 tdi goes out again and again or not at all

Hello We have a problem with our Lt 35 2.8tdi built in 1998. It started with a climper in the engine compartment. We thought it was the gearbox, however it turned out that a front wheel was defective and that caused this climpering. So motor out and new installed. In the train let the leaking diesel pump at bosch overtake and the motor including pump to set away. 3weeks. Later motor picked up and aalles again built together. Unaired and organized. Result he sp so let it be set again in the workshop. Today picked up again does not jump on … Some startspray. Given and see as he came .I thought about it. It started and immediately again. He doesn’t do anything more. Who can help me? Desperate slowly. Hope on help Mfg Jörg Mbk is AGK