16V auto passat TB - nipple for butterfly bypass?

[mk1mark at gmail.com (Mark F.)]

Hi list,

I'm having trouble establishing an idle on my ABA/JH swap.  I have
installed a 16v auto passat TB for the idle/WOT switches (the only TB
I had lying around that had them).  This TB doesn't have an idle
adjustment screw, so I made my own with a bolt and a plastic "T" -
plumbed in to take air from the bottom of the rubber boot in front of
the TB and route it to the nipple on the TB.  The problem is that even
with a totally clear tube in place ("T" removed) it still won't idle -
no matter what ignition timing I try.  The idle valve (bolted to the
back of the intake manifold) tested to work perfectly, and there are
no vacuum leaks that I can see.  I have attempted to set the ignition
timing at the lowest idle I can hold with the throttle cable, but
since the idle switch isn't engaged (and not sending a closed throttle
signal to the knock box) I doubt it's accurate...

I've double checked the cam timing, and it's dead on.

Any guesses what might be wrong?  Mayhaps that nipple isn't a butterfly bypass?

Thanks,

Mark.
75
82
82 Caddy
93 Chevy/Kia 1/2 ton