Silly me...  I took large portions of the front end of my car apart and
didn't take any notes.  I have a 90 GLI (2L 16V CIS-E Motronic), there
are two vacuum lines coming out of the bottom of the boot in front of the
throttle body.  One appears to be routed back to the air box.  The other
appears to be about 22" (just a guess) long and seems to be routed past
the exhaust manifold toward the distributor or ignition coil, but I
haven't a clue where it goes.  Can anyone help me out here?

Thanks,
dan