I have previously replaced the temp II sensor. What other sensors should I
check? What about the temp I?

Thanks,
Ken

The Bus Depot wrote:

> > My '85 is running better with the O2 sensor disconnected. I have a problem
> > at idle and when accelerating from a stop when the engine is cold with the
> > O2 sensor connected. I have tried a generic no name from Napa and then
> > went to the generic Bosch with wire from an old one. Neither made any
> > difference.
> >
> > Any ideas?
>
> Unless I am greatly mistaken, the ECU has a "factory default" mode that it
> will revert to if it cannot get a recognizeable reading from one of the
> sensors that it relies on.  In its default mode, it will ignore the readings
> from several of the F.I. sensors and use its own factory preset.  Therefore,
> disconnecting one sensor (such as the 02 sensor) essentially removes several
> from the circuit, any of which could be the faulty one which is causing the
> van to run improperly.
>
> Another possibiliy (although less likely given your symptoms) is that in the
> past someone has adjusted the fuel mixture based on the existence of an 02
> sensor that was giving incorrect readings.  Now that you have installed one
> that does work properly, this "compensating" fuel adjustment is causing the
> mixture to be way off.  You may want to have a shop with emissions testing
> equipment look at your emissions levels.
>
> - Ron Salmon
>  The Bus Depot
>  http://www.busdepot.com
>  (215) 234-VWVW