Tach problem on 80q Turbo Conversion

[Jim Green]

--- blarson at Zeiss.com wrote:
> I am helping my friend finish his 1990 80q that he
> put a mc-1 motor into,
> and even though the car seems to be wired exactly
> the same as my 1988 80tq,
> we can not get his tach working.  The car runs and
> starts fine, so there is
> a tach signal to the fuel pump relay, and the fuel
> pump relay ground is
> working correctly.  And the power and ground to the
> MAC11 seem to be
> working fine.
>
> Car: 1990 Audi 80Q w/autocheck system.
> Turbo Conversion Motor: MC 10V w/MAC 11C.
>
> Description of Issue:  Turbo conversion is done and
> the car starts and
> runs, but the tachometer does not work.  The
> violet/black wire from the 5K
> kostell 14B connector is connected in the
> green/black from the T26
> connector under the instrument panel. 
> Troubleshooting performed to date
> involved swapping instrument clusters and verifying
> the signal from the
> violet/black wire.  The wire is putting out a
> voltage and the instrument
> cluster swap did not result in a working Tach.
>
> I am wondering if anyone could make some suggestions
> on what to try next?
>
> Also, has anyone gotten the dynamic oil pressure
> system working correctly
> on a turbo converted car?


Hah!  I JUST figured all this out, after three years.
You want to use the green/blue wires going into the
tach/auto check.  I think they are on the bottom plug
in that mess of plugs under the dash.  Somehow my tach
has always worked, but my damn oil light would always
flash.  Then when I put in the lasts fuel and ign ECU,
my tach stopped working and I had to redo some stuff.
Javad helped me get my head screwed on strait, found
the two green/blue wires, hooked them up, and
everything works great.  They're in the bently, but
let me know if you need more info and I can get it for
you tonight.


=====
Jim Green
'89 90tq 034EFI Stage II
http://www.geocities.com/jeg1976/car_home.html

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