Re: Trip computer in 85 4000Q

[Tony Lum <tlum@flash.net>]

At 09:55 AM 5/7/99 -0400, you wrote:
>Installed one from wreck and everything works except it always saws low 
>mileage (ie like 10 mpg less than actual).  Is this typical or do they work 
>better.  I've tried the adjustments in the manual but no help.  I didn't do 
>the major stuff with the under hood with the sensor but the car has and still 
>runs 
>fine.

Hi there,

You need to swap the matching ecu with the trip computer, the CIS
enrichment signal is different and that's what's throwing the MPG off.  In
the interim you can set the consumption switches for the full (-) setting.
If you don't have the ecu, you'll have to scale the output with a resistive
attenuator.  Off the top of my head, the CIS enrichment signal is about
0-1.5V.  I couldn't get my conversion to work either until I replaced my
original ecu with the one that came with the trip computer.

HTH,

--
Tony
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Tony Lum                                  1987 5000CS Turbo Quattro
Berkeley, California, U.S.A.                1985 4000CS Quattro
Audi Owner/Driver/Mechanic by Necessity ;^)   1980 5000S Sedan
QCUSA Member #6885                            1987.5 Coupe GT
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