I'm not near my car at the moment so I can't let you have more info.
It's the brass/copper looking adjusting screw near the throttle idle position microswitch detector. I think the 'head' of it is 'hexgon' shaped, possibly with a screwdriver slot. It was explained to me by the true expert that sorted this problem on my 16v, that the 'muck' on the end of the valve (which if if I can recall was not needle shaped but I think 'domed') was causing an intermittaent flow of air past it into injection system which in turn could not work out what was going on when the engine revs reduced. Every time I came to a halt, whether from say cruising down the motorway or just stop/go town driving the engine would stall - absolutley every time. He cleaned the end of the valve and it is was magic - a complete 100% cure in less than 5 minutes - very impressive, but then again he was an expert and he was an independent VW/Audio dealer. Kind regards, yt.
