Just to help you visualize it, you are trying to set the timing within a window.
-2.02*...........0...........+2.02*
The stepper motor can move the timing back and forth. By physically moving the IP to the passenger side or to the drivers side, you are...
http://dieseltowingresource.com/images/smilies/iagree.gif
...and wrong torque on the lug nuts can cause warped rotors.
Re-torque and take a ride to see if the wavy rotors straightened out.
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