Date: Thu, 11 Sep 2008 14:59:33 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Question about temp II sensor and bad running
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I don't claim to know everything about this.........but I for sure know how
to check if they're working right.
but I believe if you just plug into the 02 and it's not connected to the ECU
......
you will just see a voltage output from the 02.
when you tap into the working circuit........you see the Duty Cycle of
swinging voltages, and that's what you want to see.
If the voltageis a steady reading, like .5 volts. , then you have a dead 02.
if it's very lazy responding or swinging the voltages are slow.........then
it's tired.
Not sure if you can get a reading though, since it craps out pretty quickly
with the 02 connected..
and Mark's thing about a bad injector, and how the ECU will make up for that
with the 02 disconnected........
very good thing to consider as a possibility.
I only find a bad injector about one out of 200 of them .............ro one
in 400.
but I just tried a whole fuel rail onto an engine recently.............and
it was backfiring in the muffler very obviously.......usually that's an
injector that's worn and spraying way too much fuel.
also........I don't see people doing this enough ..............but always
look at the plugs.
if you, for example, found one very wet or black with heavy carbon
deposits.............and the others were normal...........you'd immediately
think about that injector.
and once again.............a simple test that might reveal some useful
information.
It's my perception that people don't think to do that very often when they
are having a weird problem - look at the plugs.
they do offer one of your best in-cylinder inspection glues, after all.
I always treat the fuel with a high quality injector cleaner on a new used
vanagon, or one that hasn't run in a long time.
----- Original Message -----
From: "Jim Felder" <jim.felder@gmail.com>
To: "Scott Daniel - Turbovans" <scottdaniel@turbovans.com>
Cc: <vanagon@gerry.vanagon.com>
Sent: Thursday, September 11, 2008 2:18 PM
Subject: Re: Question about temp II sensor and bad running
> So Scott, you're saying to keep the O2 sensor connected to the sensor
> and check it that way? I don't see why you can't just put probes in
> the sensor half of the plug and do it that way.
>
> Jim
>
> On Thu, Sep 11, 2008 at 3:53 PM, Scott Daniel - Turbovans
> <scottdaniel@turbovans.com> wrote:
>> the test for how well your 02 sensor is working takes but a minute or
>> two..
>> super easy to do.
>> Just connect a digital voltmeter to the signal wire, ( while leaving the
>> 02
>> signal wire still connected into the system...........)
>> engine idling and warmed up. You'd like to see swinging voltage from
>> perhaps .4 volts to .8 volts......
>> something like that.
>> if it doesn't swing over a very large range, or swings pretty slowly,
>> that's
>> a lazy 02.
>> If it sits at one voltage, it's dead.
>> This simple check could/should be part of any regular checking or
>> inspecting
>> of the engine, its settings and tune up parts, and so forth.
>> and I find that tune up parts barely, barely wear on waterboxers engines.
>> Like they have to be pretty bad before they start affecting how it runs.
>>
>> ----- Original Message -----
>> From: "Jack R." <jack007@COMCAST.NET>
>> To: <vanagon@GERRY.VANAGON.COM>
>> Sent: Thursday, September 11, 2008 12:27 PM
>> Subject: Re: Question about temp II sensor and bad running
>>
>>
>>> What a great exercise!!! We all felt your pain, and relief!
>>>
>>> Glad you tracked it down to an O2 Sensor. It is BEST to replace, gas
>>> mileage, motor running too rich or lean, etc. Don't go too long without
>>> it.
>>>
>>> Now, if I can remember this when my 02 Sensor fails!
>>> Too bad we don't have "Check Engine" lights on our vans.
>>>
>>> Jack
>>>
>>> -----Original Message-----
>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>>> Of
>>> Jim Felder
>>> Sent: Thursday, September 11, 2008 3:00 PM
>>> To: vanagon@GERRY.VANAGON.COM
>>> Subject: Re: Question about temp II sensor and bad running
>>>
>>> And the loser is.... the oxygen sensor and the winners are those who
>>> suggested that I remove it from the loop.
>>>
>>> I just went for a five minute test drive and the van drove great.
>>>
>>> Now, what's the downside of running without an O2 sensor? There must
>>> be one. Mileage?
>>>
>>> I think I even have a good one somewhere. I usually replace them every
>>> couple of years but I never knew why. I do now! The last one I took
>>> out is probably good and I think I saved it. In the time it takes to
>>> find one or buy a new one, I wanted to know if there is a danger in
>>> driving with it disconnected.
>>>
>>> Jim
>>>
>>> On Thu, Sep 11, 2008 at 1:46 PM, Jim Felder <jim.felder@gmail.com>
>>> wrote:
>>>>
>>>> OK, here's the news: I just went out and tried it again and it
>>>> stumbled to a stall in about a minute.
>>>>
>>>> Then I disconnected the O2 sensor. It ran strongly for five minutes or
>>>> so, longer than at any other time today. Then while it was running, I
>>>> plugged it back in and it was dead in 30 seconds.
>>>>
>>>> I will try to repeat this again in a few minutes to confirm what I
>>>> think just happened.
>>>>
>>>> Jim
>>>>
>>
----- Original Message -----
From: "Jim Felder" <jim.felder@gmail.com>
To: "Scott Daniel - Turbovans" <scottdaniel@turbovans.com>
Cc: <vanagon@gerry.vanagon.com>
Sent: Thursday, September 11, 2008 2:18 PM
Subject: Re: Question about temp II sensor and bad running
> So Scott, you're saying to keep the O2 sensor connected to the sensor
> and check it that way? I don't see why you can't just put probes in
> the sensor half of the plug and do it that way.
>
> Jim
>
> On Thu, Sep 11, 2008 at 3:53 PM, Scott Daniel - Turbovans
> <scottdaniel@turbovans.com> wrote:
>> the test for how well your 02 sensor is working takes but a minute or
>> two..
>> super easy to do.
>> Just connect a digital voltmeter to the signal wire, ( while leaving the
>> 02
>> signal wire still connected into the system...........)
>> engine idling and warmed up. You'd like to see swinging voltage from
>> perhaps .4 volts to .8 volts......
>> something like that.
>> if it doesn't swing over a very large range, or swings pretty slowly,
>> that's
>> a lazy 02.
>> If it sits at one voltage, it's dead.
>> This simple check could/should be part of any regular checking or
>> inspecting
>> of the engine, its settings and tune up parts, and so forth.
>> and I find that tune up parts barely, barely wear on waterboxers engines.
>> Like they have to be pretty bad before they start affecting how it runs.
>>
>> ----- Original Message -----
>> From: "Jack R." <jack007@COMCAST.NET>
>> To: <vanagon@GERRY.VANAGON.COM>
>> Sent: Thursday, September 11, 2008 12:27 PM
>> Subject: Re: Question about temp II sensor and bad running
>>
>>
>>> What a great exercise!!! We all felt your pain, and relief!
>>>
>>> Glad you tracked it down to an O2 Sensor. It is BEST to replace, gas
>>> mileage, motor running too rich or lean, etc. Don't go too long without
>>> it.
>>>
>>> Now, if I can remember this when my 02 Sensor fails!
>>> Too bad we don't have "Check Engine" lights on our vans.
>>>
>>> Jack
>>>
>>> -----Original Message-----
>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>>> Of
>>> Jim Felder
>>> Sent: Thursday, September 11, 2008 3:00 PM
>>> To: vanagon@GERRY.VANAGON.COM
>>> Subject: Re: Question about temp II sensor and bad running
>>>
>>> And the loser is.... the oxygen sensor and the winners are those who
>>> suggested that I remove it from the loop.
>>>
>>> I just went for a five minute test drive and the van drove great.
>>>
>>> Now, what's the downside of running without an O2 sensor? There must
>>> be one. Mileage?
>>>
>>> I think I even have a good one somewhere. I usually replace them every
>>> couple of years but I never knew why. I do now! The last one I took
>>> out is probably good and I think I saved it. In the time it takes to
>>> find one or buy a new one, I wanted to know if there is a danger in
>>> driving with it disconnected.
>>>
>>> Jim
>>>
>>> On Thu, Sep 11, 2008 at 1:46 PM, Jim Felder <jim.felder@gmail.com>
>>> wrote:
>>>>
>>>> OK, here's the news: I just went out and tried it again and it
>>>> stumbled to a stall in about a minute.
>>>>
>>>> Then I disconnected the O2 sensor. It ran strongly for five minutes or
>>>> so, longer than at any other time today. Then while it was running, I
>>>> plugged it back in and it was dead in 30 seconds.
>>>>
>>>> I will try to repeat this again in a few minutes to confirm what I
>>>> think just happened.
>>>>
>>>> Jim
>>>>
>>
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