provided originally by GVK_motorsport
more info provided by VENTO GTI EDITION
This link has some good advice , the only thing that I would change/add is that the when the 16V s first came out they tended to suffer with idle/stalling problems .
1) I believe that the ignition should be switched off when disconnecting and connecting the red lead .
2) VW sent updated tuning data which if I remember correctly stated that the idle speed should be adjusted to 1000 +/- 50 rpm instead of the previously stated 950 +/- 50 rpm
3) make sure the throttle cable is not too tight so as not to allow the throttle idle switch to close .( I had a customer that kept fiddling with the cable adjustment on his and then wondered why it kept stalling .... the penny eventually dropped ! ....now it idles properly .ÂÂÂ
P.S. I also have changed the idle stabilization valves for modified ones ( modded ones had a yellow sticker on them ) but this was back in the 80s so I would imagine they have all been done by now unless some may not have being that it was not a recall as such.