I've had the same thing on my 82 SC for a long time so I hope when "dano" finds his solution he will post it here so I can try that on mine first... (I live with it because I've got so many other things to fix that I haven't gotten into determining the cause yet though I'm certain it's in the fuel system).
I've also got 2 Bosch K-Jetronic manuals and the troubleshooting charts point thusly (and I quote, sorta - can't draw the charts here in text):
Poor idle - cold =
-Airflow sensor -or-
-Warm-up regulator -or-
-Cold start valve -or-
-Thermo-time switch -or-
-Auxiliary-air device -or-
-Pressure actuator -or-
-Throttle switch
Well, I guess that didn't help much, but it's better than replacing/testing everything, huh?
