Please let me know when you find solution to problem.  I have same on an '84.  I am trying O2 sensor first as I am replacing exhaust system as soon as parts arrive.  My AFM is only a year old.

John
    -----Original Message-----
    From: Cam Murphy <murphys@HS-ONLINE.DE>
    To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
    Date: Thursday, March 25, 1999 9:51 AM
    Subject: AFM or OXS?
    
    
    On a cold (or cool) start my 84 Westy runs and idles fine.  Once it warms up a little it runs very rough and in an oscillating manner.  On a warm start it also runs rough.  Once it cools down for an undefined period of time, it then idles OK again until warmed up.  Overall the performance appears normal, except at idle. 
     
    Is this most likely an AFM or O2 sensor, or something else?  Unfortunately I do not have the tools (or the know-how) to verify bad parts. 
     
    Any guesses are appreciated.
     
    (Note: I have had this problem before and after the engine replacement.)
     
    '84 Westy 106k miles
    (10k on Cdn VW remanufactured engine) 
    Cam Murphy

[text/html]