Re: Lousy fuel economy on '91 200TQW; advice, please.

["Fred Munro" <munrof@isys.ca>]

Jim;

    Why don't you make up a bar gauge to measure O2 sensor output while
driving? It should give you some insight into how rich the fuel mixture is
under different operating conditions. I plan to whip one of these up for my
S4 when I get a chance (and a LM3914 chip).
    Check out
http://efi332.eng.ohio-state.edu/diy_efi/projects/projects.html

Fred Munro
'94 S4  94k km


----- Original Message -----
From: "James Desveaux" <desveaux@ucla.edu>
To: <quattro@audifans.com>
Sent: Monday, December 13, 1999 3:33 PM
Subject: RE: Lousy fuel economy on '91 200TQW; advice, please.


> Thanks for the input so far (however limited).  I suppose I should do a
> backpressure test on the exhaust, though I doubt this is it.  The exhaust
> seems okay, and there are two cats on this car in parallel.  Perhaps
> another option is to throw another O2 sensor on it that hopefully leans
out
> the mixture a bit.  The mystery to me that the exhaust is very very clean,
> so is emissions, yet I'm barely getting 13mpg around town.
>
> Is there an easy way to tell if an injector is leaking?  (the injector
> solenoids are working fine)
>
> Thanks.
>
> - Jim
>
>
>
>
> >>Fred Munro wrote:
> >>>
> >>> Hi Jim;
> >>>
> >>>     Your city mileage is not far off what I was getting with my '91
200q -
> >>> mine was around 13-14 mpUSg.
> >>
> >>I guess there could be a big variation between what's considered "city"
> >>driving,
> >>but when my wife used our '91 200Q for almost exclusively short trips,
we
> used
> >>to get around 19 mpg.
> >>
> >>I drive it now 80 miles everyday, almost all freeway, but with at least
20
> >>minutes of stop-and-go per day. I average about 45 mph from
fill-to-fill, and
> >>get something like 22-23 mpg. If I'm all alone and I drive at a steady
75
> >>mph, I
> >>get a little over 25 mpg.
> >>
> >>The lowest mileage I ever got was 10.3 mpg, after several laps at the
> >>Thunderhill track.
> >>
> >>From my experience, I feel that 13-14 mpg is a bit low, though I'm at a
> >loss to
> >>offer any advice, given Jim's fairly exhaustive checks.
> >>
> >>-Arun
> >>
> >>'91 200Q, 109K
> >>
> >>--
> >>Arun Rao
> >>Pixar Animation Studios
> >>Pt. Richmond, CA 94804
> >>(510) 620-3526
>
>