I’m pretty darned sure that the reason that DHs prediction was correct is that if any 1 of the

sensors that the ECU gets data from for Fuel Management is disconnected the ECU will go into Open Loop

& ignore all or most Fuel Management Sensor Data ~

        Disclaimer > Not Absolutely sure due to 77Yr Old Brain ~

	

> On 27 Jul , 2022, at 10:09 AM, Eric Caron <ericcaron96@COMCAST.NET> wrote:
> 
> Hi Dave,
> 
>        Sadly that is well known as a unlikely cure.  The sensor tested out fine.  But due to a needed muffler a new one went in.  It also tests out perfectly.
> 
> Interestingly, Dennis predicted this would be the case and that it would be something else in the system. 
> 
> It will be so interesting and satisfying to solve this mystery.
> 
> Keep the tips coming.
> 
> Eric Caron 
> 84 2.3 GW with 1.9 fuel management 
> 
> 
> 
>> On Jul 27, 2022, at 11:57 AM, David McNeely <davmcneely40@GMAIL.COM> wrote:
>> 
>> So if the problem only manifests itself with the O2 sensor plugged in, put
>> in a new O2 sensor.
>> 
>> On Wed, Jul 27, 2022 at 6:23 AM Eric Caron <ericcaron96@comcast.net> wrote:
>> 
>>> Hi collective mechanical mind.
>>> 
>>> Reporting back still not solved running issue on 2.3 with 1.9 fuel
>>> management.
>>> 
>>> Many steps still not done as friends are busy and summer is full of
>>> activities.
>>> 
>>> Issue is still.
>>> 
>>> Van idles high.
>>> Screw for idle control closed to max.
>>> Checked for vacuum leaks and not finding them.
>>> Tried to check timing but idle too high about 1,000 rpm and now and then a
>>> surge to 1,200 RPM .
>>> 
>>> Engine  stumbles only when O2 plugged in and engine warm.  From a stop
>>> press excellerator and 2 out of three times it will hesitate stumble or
>>> skip.  Then find itself and go.  No O2 and it seems fine.
>>> 
>>> Still need to try a friends ECU
>>> 
>>> I’m hoping to soon have most of a recently working 1.9 ignition system to
>>> have for testing and spares.  I know diagnostics is better but still having
>>> working spares will make maintaining the old system easier.
>>> 
>>> I don’t need it to be perfect but this skip and running rich needs to be
>>> resolved.
>>> 
>>> Other then this van is currently ready for a long distance trip.
>>> I recently discovered that a long term friend from bus events has a twin
>>> to my van, year, color, and even the engine and fuel management.  Currently
>>> enjoying a trip up and down the east coast.  This gives me hope for a good
>>> running van in the future.
>>> 
>>> Any additional tips are always appreciated.
>>> 
>>> Eric Caron
>>> 
>>> 84 GW 2.3 with 1.9 fuel management
>>>