[urq] Running Rich issue solved!

[Ingo Rautenberg]

Very useful test procedure, L-A

Thanks!

Ingo

On Feb 26, 2007, at 4:08 PM, Louis-Alain Richard wrote:

> Bravo Mike ! One less to worry about. Now, Keith, a little effort
> please :-)
>
> Mike,
> 2 questions come to my mind:
> - Did you sealed any engine parts (valve cover, water pump, etc.) with
> RTV silicone recently ? The standard silicone was responsible for O2
> sensor failures in the eighties, IIRW.
> - Did you test the dead O2 sensor to confirm that it is indeed dead as
> a doornail ? If not, you can do it easily with a propane torch. Read
> this procedure from this site:
> 	http://www.gnttype.org/techarea/ecmsensors/O2sensors.html
>
>
> Testing O2 sensors on the workbench.
>
>        Use a high impedance DC voltmeter as above. Clamp the sensor  
> in a
> vice, or use a plier or vice-grip to hold it. Clamp your negative
> voltmeter lead to the case, and the positive to the output wire. Use a
> propane torch set to high and the inner blue flame tip to heat the
> fluted or perforated area of the sensor. You should see a DC  
> voltage of
> at least 0.6 within 20 seconds. If not, most likely cause is open
> circuit internally or lead fouling. If OK so far, remove from flame.
> You should see a drop to under 0.1 volt within 4 seconds. If not  
> likely
> silicone fouled. If still OK, heat for two full minutes and watch for
> drops in voltage. Sometimes, the internal connections will open up
> under heat. This is the same a loose wire and is a failure. If the
> sensor is OK at this point, and will switch from high to low  
> quickly as
> you move the flame, the sensor is good. Bear in mind that good or bad
> is relative, with port fuel injection needing faster information than
> carbureted systems.
>
>        ANY O2 sensor that will generate 0.9 volts or more when heated,
> show 0.1 volts or less within one second of flame removal, AND pass  
> the
> two minute heat test is good regardless of age. When replacing a
> sensor, don't miss the opportunity to use the test above on the
> replacement. This will calibrate your evaluation skills and save you
> money in the future. There is almost always *no* benefit in replacing
> an oxygen sensor that will pass the test in the first line of this
> paragraph.
>
>
> Louis-Alain
>
>> Finally figured out my "super rich" running problem. It was the  
>> Oxygen
>> sensor! I replaced it last year just as a "preventative maintenance"
>> thing, so I
>> didn't think it would be bad. Luckily I try and stock extra parts for
>> times
>> like  this and I had a new OX sensor. I was ready to replace the
>> injectors and
>> the  WUR!. So perhaps if someone else has a rich (or maybe lean)
>> condition, try
>> the  ox sensor. It's a bitch to get at too.
>>
>>
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