[wakespeak]

Great thread. In my case I checked mine and the set screw had a burr and is not flat against the angled metal hinge. The action felt hung up against the set screw. The hinge if suddenly released would bend and bind. I created some gap and used a fingernail file to deburr the back of the set screw. Then added a little preload = 1/8 turn. If I did not add the preload it felt again as if it were getting hung up. Thinking the butterfly was getting hung up by going "too far".

Edit: the system is completely open at idle. Wondering how this would affect anything but full throttle/boost. The hinge is gouged due to use so I do think it was getting hung up from time to time.