Greg:
Just solved a very similar stumble-at-cold-start problem, but not until it
got worse.
Checked all the fuel/idle system to no avail. Finally the problem advanced
to partial stalling on the go.
Mine was the O2 sensor.  Unplugged it and the stall and prewarm up stumble
went away.  A new sensor fixed it.
Stephen
>Wanted to run this by the group.  I fire up the
>vanagon after its been sitting a while.  Take off down
>the road....then, I will get a hesitation for a second
>or two where it feels like I've lost power, followed
>by a surge, whereby power returns to normal.  This
>happens three or four times until she is warmed up,
>then symptoms are gone.  It doesn't seem like a spark
>problem, it's more like something may be telling the
>AFM to restrict air, or timing is being retarded.
>Does this make sense?
>
>Greg Stelz
>86 westy
>Delaware, Ohio
>
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