Fw: Wide band O2 ????

[mr.utility at highstream.net (mr.utility@highstream.net)]

Quoting Dan Bubb <jdbubb@ix.netcom.com>:

> Dammit! I read the quote and thought "that's all effed up"!
> What I meant to say was "1. control the current to it's heater to maintain
> the sensor temperature in a
> narrow temperature range despite exhaust heat input (or lack thereof)"

Okay, I think I understand...
 
> Anyway, this sentence applies to the wide band O2, but in any event the
> heater is always on for both the narrow and wide band O2's.
> The heater is there, as you state, to get the O2 sensor to temp faster, but
> it's also pretty far down the exhaust on a 16V and may not stay hot enough at
> a consistent idle. Note, the 16V has a heater, but the 8V does not since it's
> sensor is 6" from the head.

It is also an earlier FI system, or are you talking about the 8V golfs with 
CIS-E?  If you are, then yes, I would say that must be the reason, the 
distance...

> As is turns out though heater resistance increases quite a bit as the heater
> gets hotter, so current becomes negliable. If you look at a schematic for the
> 16V engine wiring you'll see the heater is getting 12V whenever the fuel pump
> is running.
> 
> 
Hmm, then I wonder how it regulates itself as far as how hot it gets?  Perhaps 
by design, it gets up to X degrees, and stays there...  But then, that brings 
up another question...  What about age, does age affect the 'temperature 
control' of the O2?  These may be silly questions, but the more I understand 
the minutia, the more I understand how it all works together...  It is all in 
the 'patterns'....

David

>   ----- Original Message ----- 
>   From: mr.utility@highstream.net 
>   To: Dan Bubb 
>   Cc: scirocco-l@scirocco.org ; Ron Pieper 
>   Sent: Friday, October 24, 2003 2:29 PM
>   Subject: Re: Fw: Wide band O2 ????
> 
> 
>   Quoting Dan Bubb <jdbubb@ix.netcom.com>:
> 
> 
>   > 1. control the current to it's heater to maintain the sensor temperature
> in a
>   > narrow band despite exhaust heat input (or lack thereof) 
> 
>   > Dan
>   > 
>   > 
> 
> 
>   Correct me if I am wrong, but the only time the heater is used is at
> initial 
>   start-up, when the sensor is cold?  I was under the impression that that
> was 
>   the only time the heater is used, to further diminish emissions when the O2
> is 
>   cold and not yet able to function completely....
> 
>   David
> 
> 
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