Anyone have any idea what this part is and what it does? The white "cap" has what appears to be a vacuum nipple that's been broken off, but I can't find a line that would go to it. The part's just downstream of the AFM outlet boot, about even with the throttle body. It's linked to the throttle rod and sounds like there's a diaphragm inside when the throttle linkage is rotated.

That's a dashpot. No line connects to it, that cap is just a vent and your's has the tip broken off. It dampens the closing of the throttle just prior to the point where it's completely closed.

cool beans. thought it might be, but wasn't sure. haven't heard of one since I dealt with the carbs.. thanks, Steve. as always, you're s wealth of information.