Strange problem I have just rebuilt my engine and at first it was lumpy on tickover and when not on boost. When the car came on boost was perfect.
I investigated the lumpy running and did a fuel pressure test spark test ect. The act of testing this seemed to sort it.
Since then it noe idles perfectly and is perfect on boost, but when driving not on boost still lumpy as if on 3 cylinders.

 

timing ok?

 

Going to have to double check it I think