Date:         Mon, 18 Dec 2000 16:36:19 -0500
Reply-To:     James Creech <jacreech@VISUALLINK.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         James Creech <jacreech@VISUALLINK.COM>
Subject:      O2 voltage when cold
Content-Type: text/plain; charset="iso-8859-1"

Anyone with a Digitool or who has otherwise measured the voltage the O2
sensor puts out at cold idle (first start up)?  I am trying to diagnose my
cold idle problem and have eliminated most everything.  However, I noticed
today with the Digitool connected (great tool, Darrell!) that my cold start
up gives an O2 reading of 400 mV which slowly rises to about 650 mV.  The
engine won't keep running and needs several starts at that lower voltage
until it rises to about 500 mV, at which point the engine stays running
(idle) - from there up to about 650 mV, which I'm guessing is the correct
idle enrichment value.  Then a couple of minutes later the ECU goes into
closed loop and my O2 readings vary above and below 500 mV, as they should.

All my other components seem ok (temp 2, AFM, idle stab. valve and its
control unit all test ok).  Does the fact that my engine stalls out at cold
start up with the low voltage reading at the O2 sensor (400 mV) say anything
helpful to diagnose my problem?  BTW my O2 sensor is the heated type.
Perhaps the slow rise from 400 mV to 650 is only due to it heating up?

Thanks,
Jim Creech
87 Westy 2.1