Strange temperature sensor problem solved. Thanks !

[thyrsted@olsy.dk (Kenn Thyrsted Nielsen)]

Hi.
I've solved my problem, wich, as you pointed out, was caused by the
temp-sensor.
At first i superficially checked the temp-sensor using an ohmmeter, and just
moving the wires a bit, wich only indicated that it was OK.
But as i had the 3000rpm code translated, i looked more thorough.
About 5 inches from the sensor i discovered a point where it very seldom was
possible to cause an open circuit, thus disconnecting the sensor.
Being fairly satisfied with myself, i poked around with the wire very
carefully to ensure that i really found the culprit.
I had.
-Or sort of...
In addition i found what probably caused the engine check-light; the solder
terminals was so close together, that the protective heat-shrink isolation
over time cracked, allowing a sporadic short circuit of the sensor.
Cutting the old heat-shrink very carefully with a knife and then again very
carefully moving the terminals a bit further apart solved that.
Replacing the bad 4" piece of wire with 8" multicore soft wire allowing for
vibration solved the wire problem.
(I left about 1" on the terminals, because the soldering was OK)

Now the engine is providing more torque between 2k and 3k than ever before,
and what seemed to be an sporadic hesitation under light throttle is
completely gone.

Thanks !

Kenn Thyrsted
'87 200TQAvant


-----Original Message-----
From: Ti Kan <ti@amb.org>
To: Kenn Thyrsted Nielsen <thyrsted@olsy.dk>
Cc: Audi Mailing List <quattro@coimbra.ans.net>
Date: 29. august 1998 18:06
Subject: Re: In persuit if the infamous codes the rev counter jumps to
7200rpm, and other anomalies..


>Kenn Thyrsted Nielsen writes:
>> You describe the code pulling sequence for the older MAC's, and is
referring
>> to the "Bentley chart".
>> Therefore i hope you can translate a code for me.
>> In short: I need to know what it means when the tach reads 3000rpm with
the
>> engine check light ON.
>>
>> The long story is that i'm experiencing an periodic problem:
>> Recently the engine check light is coming on under light to medium
>> acceleration.
>> (also under full throttle, but i only checked this once)
>> Slightly backing off the throttle makes the light dissapear, and i can
feel
>> the engine pulling more willingly (not much).
>>
>> I pulled the codes; it said 3000rpm (MAC 06A).
>
>For the MAC-07 computer that is on my 84 5KST, this indicates a fault
>in the intake air temperature sensor.  I don't know if the MAC-06A
>is the same, but it's likely.  The intake air temp sensor is the
>little black plastic gizmo with a black cable coming off of it,
>mounted on the intake manifold near the throttle valve.  Before
>you replace it, first check the solder connection on it to make sure
>that isn't the problem.  Peel back the rubber boot on the sensor
>to check.  It's soldered with high-temp silver solder.
>
>-Ti
>96 A4 2.8 quattro
>84 5000S 2.1 turbo
>80 4000 2.0
>--
>    ///  Ti Kan                Vorsprung durch Technik
>   ///   AMB Research Laboratories, Sunnyvale, CA. USA
>  ///    ti@amb.org
> //////  http://sunsite.unc.edu/tkan/
>///
>