Making a slightly-educated guess, that sounds like a sensor may have been damaged. Since it's so specific I'm willing to bet it's electronic-related, at any rate... seems like physical damage to the throttle assembly would show up regardless of where the tube is turned. Of course, that and a $1.00 will buy you a cup of coffee at... someplace they've got coffee for $1.00.
Good luck! I'm sure others will be along with vast amounts more technical expertise than I to help you out very soon.
Peace
Dave