the truck drove and preformed great was pulling a load and a loud knock started found it was a failed cam shaft. decided to replace motor for a time saving value. a reman was installed with my jakes, turbo(35lb), fuel pump, injectors, unit pumps, starter, compressor, a/c, and the new add-ons inclued new altenator, water pump, oil cooler. since i got the truck back it will only put out 19 lbs boost, and the pyro even on a big hill,pulling a 80000 lbs load wont climb above 750 degrees, and motor temp wont go above 200. The fuel pressure is at 75 lbs, we had a shop computor installed and programed to the unit pumps, new unit pumps were installed and no change (after removed) a new turbo was installed and again no change(removed after) all working computors off of another truck were tried with no improvement. then mack decided it was time to look inside they found the pistons were right the heads were right and working (not sticking),the cam was right and all the timeing and internal settings were right. all the sensors were functioning, an external fuel source was used and that as well didnt make any difference, they concluded it wasnt the motor. After removing the other computors mine was reinstalled and found that it wouldnt reprogram after being flashed so i elected to have a new ecu installed when that didnt work they had no more ideas and sent me home to try to figure it out on my own. I have replaced the boost sensor and replaced input and output fuel lines to the secondary filter, with no change. I feel it must be electrical possibly the out put voltage to the sensors or the wiring harness was corruptted during the change over, or possiblly the new altenator was wired up wrong(14volts)? during all of this we have found the truck thinks it is getting more fuel that it is, it has a Qual-com installed and it consistently records higher fuel consumpution than what it refuels at by 5:3.5 ratio. I hope you can see where my frustation is comming from. thanks for your consideration.