Detroit series 60, non egr

Hello all, a friend of mine has asked me to check out his new western star glider with a non emissions Detroit in it. Thing was running fine up until the beginning of July where now it has no boost at low rpm and blowing thick black smoke then builds to around 30 psi above 1300rpm. I’ve already verified the wastegate is operating correctly and checked that charge air system for leaks and found none. The boost sensor was replaced with no improvement. I work on internationals for a living so I’m well versed with a Diesel engine, but every manufacturer uses different set ups and specs so any help would be much appreciated.

 

No codes, but I noticed that if we unplug any of the sensors, it still doesn’t throw a code so I’m not sure if it’s set up 100% since it’s a glider, unit was recently serviced with new fuel, oil, and air filters. Boost sensor was replaced and did not correct issue, no oil in turbo or intake system

 

I’m an international mechanic but we don’t use Detroit. I thought the turbo or sensor too, now without the proper equipment to communicate with the thing I’m at a loss as well. Guess I’ll just do some trial and error here and see what I find

 

I’ll figure out where the glider came from. Would a cam cause that on a Detroit? The problem is getting any worse or better over the last month, I would think if it was a cam then it would get progressively worse with time, but I also don’t know Detroit.