I ran into a similar situation with my '88. I am a believer that you really need
to reset the idle parameters with a CO meter when you change those components.
In my situation, I went from a very lean (old AFM) situation to a very rich (New
AFM) situation. Unfortunately, the "mechanic" who was adjusting it refused to
take my advice and used the CO port to set the idle, but insisted that just
using the tailpipe sniffer was fine. Even so, he could only barely get the CO in
spec. One fix to this was suggested to me was to open the AFM and change the
spring setting on the device.

Todd
'88 Westy

John Graham wrote:

> My tale begins with taking my Westfalia to the local VW place here in
> Charlotte NC to have a coolant leak fixed.  While you're at it, I asked that
> they look into the rough idle that had developed.  It still idled okay, but
> was just rougher than before.
>
> They did a compression check and found that one cylinder was 20 lbs lower
> than the rest but said that that was probably not the cause and I suggested
> the spend a little more time.  They 'discovered' that the air flow meter was
> not working and that the rough idle was because I was running extremely
> lean.
>
> They recommended a new AFM($500) and 'upgraded wiring harness' ($150).  I
> decided to live with the rough idle a little longer.  But later that day, I
> discovered that I could get both 'needed parts' from the Bus Depot for $119
> each.  I hadn't run out of money yet this month, so I ordered them both.
> They arrived in the promised time.
>
> There's not much to installing them.  But the idle didn't smooth out much.
> There's the hex head adjustment on the AFM; I tried turning a couple of
> turns in each direction, with no noticable effect.  My question is on this
> adjustment: Should I have gone further?  Or do I need more sophisticated
> measuring equipment like the dealer has to monitor things like CO level etc.
> ?
>
> thanks in advance for sharing your experience in this area.
> John Graham
>
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