Well I have Fitted the carb with a new pull-down choke and Replaced the vacuum on the dizzy which was not holding vacuum well. Checked the wax stat which works and checked the resistance of all the ignition parts. Rechecked dynamic timing. So all the component parts work now and the car absolutely flys.
I have just plugged the open port as I am now almost 100% convinced that this should have a plug (or is a take off for the econometer or automatic gearbox). I think the plug has always been missing or that the car has back fired and launched it somewhere.
I have bought a vacuum tester (ebay 15quid) in order to set up the rest of the 2E. It still seems very rich ticking over (when warmed up) and I think the whole carb has been played with and I need to reset it.
I have found a link thru this forum to a more detailed set-up of a pierburg 2e(2) which I found helpful. The Haynes coupe manual is very sketchy and doesn't cover the workings properly in the supplement at the back. It is not a link for the Audi carb but it gives a bit more basic info.
http://www.clubgti.com/showthread.ph...urg-2e-problem
What I am really after is an official Pierburg audi 80 90hp set-up manual. Or a VAG workshop manual covering the 2E for the audi application.
On a steep learning but happy to help anybody with similar B2 woes