CO Mixture Adjustment on '87 5KCSQT

["Bill Rowe, CFO" <browe@gtminet.net>]

Does my car use CIS, CIS-E, or CIS-E III fuel injection?  Could never figure
that out.  OK, so I'm a dumbass.  Anyway, here's my problem.  Played w/ the
co mixture adjustment a while back but didn't make note of my starting
point, not that I knew for sure it was correct to begin w/, so now I don't
know if I'm running lean or rich or right on.  Bought car w/ 101k miles 5
yrs ago and it now has 150k.  Bought from orig owner who always took it to
dealer (now that's a dumbass,  actually he was a rich guy so I guess money
was no issue).  I've continued to maintain her properly, doing all routine
maintenance myself.  I've spent a lot of money and time keeping her running
fine but I've never had a professional shop adj the co mixture.  It's
running perfectly now except for low gas mileage (getting 18 mpg mixed
driving and close to 25 mpg hiway but I average about 75-80 mph... maybe
that's normal???)so I wonder about the co mixture... is it right or can it
be improved.  I just replaced the OXS and want to make sure I maximize gas
mileage.  I know on the older VW's w/ CIS you could adj the co mixture by
turning out counterclockwise until car falters and then turn in clockwise a
1/2 turn and voila.  Will that work on my 5KCSQT?  I know it's not a perfect
method but is it close enough?  Yeah, I know the Bentley procedure but I
don't have the right testing equipment and even if I did I'm not sure I
could pull it off.  Any suggestions/advice???  Thanx.