Nailing engine driving me crazy
 

Sorry for my first post to be an asking for help post, but this problem is driving me up the wall. My 190d 2.5 is nailing badly from idle up until about 1.5k rpm at which it turns smooth. From idle to 1.5k rpm it also smokes excessively, both visually and non-visually (you can smell the fumes). So far, I've had the injectors rebuilt and the timing chain checked, which was fine. I have a video of it nailing here: https://www.youtube.com/watch?v=WnS-1DLA1JY


What could be causing this?