Ducato 250 , no diesel pressure

Hello together, I’m in despair with my Duc. Two weeks ago my Ducato changed the head gasket. So far so good, everything was built together properly and tightened with torque. Fuel system ventilated and after a good half hour the engine then ran as well. Now to my problem : 1 day later : Front again built together, cooling water in it and wanted to run the good piece warm but nothing happened, engine rotates, but does not start…. No chance, with start pilot it starts and you can keep it alive. What was done : Error read out but no error stored fuel truck measured, according to tester fluctuating between 400-700 bar, so too little leak oil checked but almost no leak oil on all 4 cylinders injectors incorrectly mounted around, so that they get into free splashing but there is not 1 tropice All fuses checked was a 40A fuse in the engine room, believe F08, defective was also exchanged but no change high pressure pump replaced again exactly the same, too little pressure cable from donors and injectors is measured by I don’t want to be able to jump all the tank.