At the risk of beating a dead horse, here's my situation.

With the TruTrak auto pilot in control, turning the autopilot knob for a 90 degree heading change produces a nice steady turn with no loss in altitude for the whole 90 degrees.

But when controlling the autopilot via the 4500 heading bug, the turn starts off ok for the first 30 degrees but then becomes a roller coaster ride, constantly trying to hold attitude by overshooting and undershooting while progressively getting worse. Once on course it settles down.

So the only thing I can think of to adjust is the ATL Gain on the EFIS. Yet no setting from 1 -12 seem to make a difference.

Any suggestions?