that great advice. As I understand the full turbo has a fuel pump that boosts the fuel when the boost rises to increase power. this is what you are saying the ECO diesel doesn't have. also I have noticed a real lag with the turbo then in really takes off. this is the spooling delay you are speaking of right? I guess the k15 would be a smoother acceleration and ultimately a similar performing turbo.
If it pulls to ONE side when accelerating and then pulls to the OTHER side when decelerating then it would be the control arm bushing. On one side or the other. You can figure out which side by which way it pulls, when.Andrew