[T3] great weekend drive

[Jim Adney]

On 30 Sep 2011 at 15:15, Bryon Garvin wrote:

> > I suspect you may be running a bit lean.  I wonder if the resistance of the
> > cylinder head temperature sensor is a bit on the low side.
> 
> 
> I find some discussion that says it should read about 2K.  Is that right?

The resistance is highly dependent on temperature, and the actual 
numbers are quite variable. The resistance comes down dramatically as 
the sensor warms up. Here's what Bosch says it should be:

at 14 F: 7-12 kOhm
at 68 F: 2-3 kOhm
at 122 F: 0.68-1.0 kOhm

I think it would be hard to tell if the sensor is at fault by looking 
at its resistance as the engine warms up. You have the chicken and 
egg problem: Is the engine hot because the resistance is low, or is 
the resistance low because the engine is hot?

Frankly, I've used lots of different temp sensors and they all seemed 
to work about the same. My guess is that they only make a difference 
during warmup and that the operating richness is determined by other 
things, like the brain and the pressure sensor.

I know lots of things that will make the system run rich, but I don't 
recall anything that makes it run lean.

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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