Isolate your idle stabilizer for an idle test. Do this by warming the engine,
then shut it down, remove the O2 sensor connector at the idle stabilizer valve,
then start engine again. Note the idle speed...850 to 950 rp,. Should not vary
more than 50 rpm. Rev engine a time or two just to see what the idle speed
does. If it drops back and idles smoothly arount 850 to 950 you problem is the
O2 sensor. If the rpm hunts wildly, then the problem is  other than the O2
sensor. You must then go to the Bentley for procedure.

John Rodgers
"88GL Driver.

Martin wrote:

> Hi All,
>
>    I'm having trouble with the idle on a didget.  The idle is erratic and
> goes from 1500+ to an immediate drop to 1000 and continually cycle quickly
> like that.  I did the test for the aux air valve as per Bentley and it
> pointed to that.  I have been driving with that hose pinched off and it
> idles and starts just fine.(20-50F)  When I replaced the aux air valve, the
> same symptoms appeared so I pinch off the hose again.  I am getting 12+
> volts to the air valve.  The air valve closes out of the van with 12v
> connected, as it should.  I could not find any vacuum leaks.  My tail pipe
> is blacker than normal and mileage might be down 1-2mpg.  The temps sensors
> were fine.  I did not get a chance to check the fuel reg. yet, that's next.
>   Any ideas?
>
> Thanks,
> Larry