RE: What's this part, nevermind.

["James A. Desveaux" <desveaux@ucla.edu>]

Ed:

I just went through a series of checks on the air temp sensor on my '91 TQW.
When you remove the sensor from your avant, you should check the resistance
of that sensor at ambient temperature (70 degrees or so).  You should get
somewhere around 500 ohms.  If you get a good reading on your V8, that
sensor might be okay as well.  Scott Mockrey's website is really thorough on
the specs for this particular sensor.  He's also got the Audi part # for the
sensor itself, the boot, and the gold plated connectors that go with it.  He
says you're supposed to carefully solder the wires to the new connector, and
then cover with shrink tubing.  The Bentley says the same thing.  The dealer
price on a new air temp sensor is about $158. and it's a dealer only part.
Carlsen, of course, is cheaper.  My understanding is that if this sensor is
defective, or not connected, the ECU goes to a default temp reading, and it
can cause the engine to run overly rich.  (That's why I was checking out mine.)

Hope this helps.

- Jim

p.s. I got a 'cold' reading of 498 ohms on my sensor, and a reading of 556
ohms about 1/2 hour after the car had been driven.  I checked it at the ECU
harness, which is where you have to check it if you don't disconnect the
wires from the sensor itself.  The range in the Bentley is 450-550 ohms.