I bought my motor off of a friend and didn’t really know the history of it. Turns out the motor was rebuilt or replaced and whoever built the motor left the VTC solenoids out of the camshafts. The plug-in for them are there but they are not actuating causing a lot of lag until about 4,000 RPM’s . Greg explained it better than that and in more detail but a long story short its robbing me of about 100 ft. lbs tq on the bottom end.