Thanks Mark I will definitely check that wire. David Clarkson -----Original Message----- From: mark drillock <mdrillock@cox.net> To: David Clarkson <dvdclarksn@AOL.COM> Cc: vanagon <vanagon@GERRY.VANAGON.COM> Sent: Fri, Dec 28, 2012 11:13 am Subject: Re: O2 sensor type problem after replacing O2 sensor The O2 heater is powered by the FP relay in 1990 so it should be heating whenever the engine is running. The ECU watches the Temp2 sensor and ignores the O2 reading unless the Temp2 shows the engine coolant temp to have reached a warm enough level. A bad or intermittent connection to the Temp2 could cause the ECU to run in cold mode and I believe that will be a rich condition. Not rich enough to kill the engine though. The ECU uses a special ground to compare the O2 reading to and if that special ground is weak or missing then it will get false readings from the O2 sensor. The special ground is the brown wire that comes out of the small bundle going to the distributor hall connector. The brown wire has nothing to do with the distributor. Make sure the brown wire has a good ring terminal crimped on to it and is bolted down to clean metal on the engine. Mark |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.