The big flathead screw on the top of the throttle body? I have never, ever heard this one before!
I've also never taken the screw all the way out before, but I would think that there's an o-ring in there somewhere, and if there is, I bet its either disintegrated, or completely missing! Either that, or there's a hidden spring inside that's either not springy any more or, again, missing. Either of those would provide enough tension to keep it from tightening or loosening.
If you do pull it out to check, make sure you back it down all the way, counting the turns until its fully seated! Then, unscrew it all the way out and take pics for us to see! I've never seen that part completely removed!
Linear Mode
