C15 MBN engine studder .

Hi fellas new to new forum and new to semis as well normally work on construction equipment, I helped a farmer friend swap a MBN C15 into his 2010 petrbilt previous Cummins isx failed , the cat engine has a studder/hunting at engine speeds from 700-1400 rpm and will only do this once coolant temp reaches 106f , on manual cruise switch or foot throttle. I also tried unplugging coolant sensor and studder will appear before engine reaches 106f , so seems to me like ecm issue any one ever come across this , I have cat et and have no codes .

 

I can do that no problem, do you know what flash file number your running ?

 

My computer tells me I can flash a 215-7402 6nz file in . I’m currently running the 272-6621 file