Just trying to stop the hunting on my 230. Firstly making sure the butterfly is fully closing on the throttle body as part of the linkage tour. I note that what should happen is when FULLY closed, it should bind slightly when trying to reopen the butterfly. I have adjusted it fully closed but it doesn't "bind" at all when opening. Should it bind? is it just a case of worn out? Its the original unit, 140k miles.