'85 4k quattro/trip computer accuracy

[Eric_R_Kissell at whirlpool.com]

"mark wolfson" <mark.wolfson at verizon.net> wrote:
>Please tell me if it is possible to correct an innacurate trip
>computer. It is reading an average of 27+mpg per tankful, when
>I am actually getting a little over 19mpg combined.

I will assume someone told you about the adjustments to adjust the trip
computer on the back of the instrument cluster.

A better question to ask is why the computer is so far off from reality. I
know the trip computer will always be somewhat inaccurate, but yours is
extremely bad.

I have always wondered if the relationship between the airflow meter pot,
which gives plate position, and the 3mm adjustment screw at the airflow
meter, which I believe adjust plunger height relative to plate position,
could fool the car into thinking it was using more/less fuel  than it
actually was.

It is probably a good idea to check some of the basic settings in your CIS
system before spending too much time adjusting the trip computer. You might
find that if you adjust your CIS correctly you can improve your actual
mileage and improve the accuracy of the trip computer at the same time.

Can anyone speculate about why his trip computer would be so optimistic?

HTH,
Eric Kissell
1991 200q 20v Avant, Koni Sports (yellow), 2.4 Bar (MRC), eBay Surprise
1989 200q 10v Avant, Boge Turbogas, 1.8 Bar (qlcc) - FOR SALE
1986 5000cstq Sedan, Bilsteins, 1.8 Bar (SJM)