I started working for a fleet that has mostly duramaxes. They are new to me i was mostly a john deer mechanic. Here is the issue ontle of our trucks an 04 3500 cab n chassis started blowing constant black smoke and would not start without assistance they took it to the dealer and found out what it needed
The dealer said to replace all fuel lines sending units, #2#7 injectors and the cp3. Thats where i came in they hired me i said sure ill try. I got everything in truck fired right up. Truck only had 52790 miles on it within 12 miles of testdriving it the same exact symptoms aroused. Anyone have ideas on possible problems? Balance rates where all within specs right after all parts installed. Now they all look to be skyrocketed. Some are upwords or 8.6 at idle when they where all around 1.4 and-1.5 12 miles ago

 

look up the ice pick trick.

the connectors to the injectors get loose and that creates a bad connection and throws everything else out. this may be the issue. quite common with the LLY #2 & 7 injectors. there is also supposed to be a TSB out on this and a repair kit for a more permanent fix.