well right now the injection pump is out at a specialty shop to have them look over everything, as for the tank we have dropped , flushed, and thoroughly cleaned the tank, so i know that is not the problem, we do still believe the issue is fuel related but until i get word form the other shop about the injectors i won't know any more. as for the fuel system we have gone through everything from the tank up to the injectors, we have replaced both the fuel shut off solenoid, the fuel feed pump was replaced with a high flow pump, the fuel lines we all replaced and the fuel system was completely flushed, and treated fuel added.
this has been one of the harder tractor issues we have had in our shop, my guys are going through the DPF system now and checking everything regarding to it just to make sure that isn't causing the issue.