I'd give huge odds I know what the problem is and why the cars acting like it has a vac leak. Basically cuz it does... but from NONE of the usuall suspects. I'll give you guys til tomorrow morning to see if ya can figger it out. Least I can go to bed, sleep now. When it's right ya just kinda know it ya know? It's the ONLY thing that makes sense.

Good news: I was looking in all the wrong places. Bad news: It's got to come out to fix it, Grrr.

Gas pedal isn't adjusted right, wait that can be done with TB on, scratch that one, so my first response!

to make sure it can go to WOT. Amazing how a throttle body can change that feature and no two are alike. But no, sorry thats not it.

And that would likely bend the arm that houses the cable adjuster. I've never seen an Audi not return to it's idle-stop but I've seen dozens that wouldn't go to WOT.

Air is leaking past the epoxy or the sleeve on the throttle body?

The only other thing I can think of is that we're not getting enough torque onto the throttle body's allen-head bolts to seal it completely?

OK... they're both incredible stretches of the imagination, but that's all I can come-up with...

Bob

Mine was held-on with 10 mm hex nuts that were only finger tight. I cleaned it out and reinstalled it (and really tightened mine down) but that didn't fix my particular problem. But maybe this is the problem that you're experiencing?

Just a guess. ;-)

torqued to 12ftlbs with a known good torque wrench.

them open at idle?

is pulling them open? The wall missing causes the vacuum created by the ICV passage to pull the secondary butterfly open?

you're so damn close I don't want to give it to you now. Think of what I did all day yesterday and unclosed butterflies. How could they be connected?

but I'm not sure what.

from closing?

What else would keep the butterflys from closing when you only took material away from the inside of the tb venturis?

that has become stuck to the butterfly sealing edge or the bore of either venturi where the sealing edge rests at closed position. Even tho it was ultrasonically cleaned it would likely not be able to loosen, fall out if the sealing edge were holding it in place. And since the plate, walls and sliver are aluminum they are soft and 'sticky', they can easily become embedded to each other under pressure. The kind of pressure found when butterfly plates are opened then released to seat themselves before being blown or cleaned out or ultrasonically cleaned.

The resultant symptoms would be two-fold, ie; vacuum leak accompanied by slightly higher idle 975 vs 850 rpm dependent on sliver thickness.

Guraranteed when I pull the TB this morning I'll be able to see a distinct hairline of light around one or both butterfly plates when holding to a light source. I just know thats it. Knew it as soon as it dawned on me.

Anyone wanna bet?

i have no money

I mean caps.

As long as its a woman involved.