Hello

I had this problem a while back, and did manage to find a diagram on the
net, unfornately I can't find it again, but you're in luck, coz, I've since
since bought a carburettor manual, I've scanned what I think will be the
correct diagram, and put it on my webserver, you should find it here,
http://82.1.64.66/Pierburg_2b7.htm (apologies if the download speed is slow,
I've only got part of a slow internet connection) if reconnecting the vac
pipes correctly doesn't solve your problem, you might need to check and see
whether the same previous keeper messed around with the idle speed/mixture
settings, and check for air leaks.
On mine, the emulsion tubes near where the PCV pipe enters the air intake,
tend to crud up every now and then, this could also be a cause of your
problem.

TTFN, Ken Phillips