That's very interesting. Thank you Geza. I have made adjustments myself to
the "idle" air screw and getting that right made a huge difference in
low-rev drivability but did not affect the 2200+ rev range where presumably
the OXS/ECU is in charge (no pun intended).
But I am not familiar with an adjustment of the AFM wiper arm - do you know
where/how that adjustment is performed?

Pat Little
'90 Westy
Seattle

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Geza Polony
Sent: Thursday, June 21, 2007 4:13 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: rough running

Did you have the mixture set with an exhaust gas analyzer?

I had the same symptoms as you're describing, slight misfire around 2500,
then ok above that. Failed smog, replaced cat and had the mixture set (not
just the idle air screw, the AFM wiper arm too) and no more misfire.

Of course this could be many things. But I mention this because I watched
them set the mixture by revving the engine to around 2500-3000 rpm, and I
could hear it even out as the mixture got closer. YMMV.