On Mon, 7 Apr 1997, Tony Moore wrote:

> Just got back from a 5 day trip and the strange idles is back! To recap,
> [snip]
> the idle with rise to around
> 3000 in park and neutral. After replacing the 02 sensor with a generic
> Bosch 3 wire, the problem was reduced to sporadic and then disappeared
> after I replaced the thermo which was stuck on open, making to bus run
> *very* cool.
> Any suggestions on where to
> begin again?

I have a theory, based only on my own experience, that unstable (high) 
idle in Vanagons can be caused by too rich a mixture.  I was experiencing 
the same problem; I replaced the O2 sensor, spark plugs, plug wires, 
distributor cap, found a working idle stabilizer, etc. and still had the 
unstable idle.  Finally determined that the air sensor was such that it 
COULD NOT be "leaned" enough to get the idle mixture into spec.  After 
fixing that (tightened the return spring in the sensor) the idle's be 
rock-steady.

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Tom Young               young@sherlock.SIMS.Berkeley.EDU
Lafayette, CA  94549    '81 Vanagon
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