The Weber does NOT have the idle-up solenoid that is on the stock carb that is used for the a/c. Really what alot of people have done is simply turn the idle screw in a little bit each summer to compensate for the rpms the a/c draws. I am sure someone has tried to add the idle solenoid to their Weber but I have not seen proof of that mod yet.
yea mine wants to die if im idling and I turn the wheel all the way real fast, due to not having that solenoid. no biggie, for things like that just up the idle sum.