Just for grins, Mike, have you tried swapping the injectors from one
side to the other to see if the indications change?

Mike

Michael Elliott wrote:
> I'm hunting for the reason that Mellow Yellow gets about 15% poorer
> mileage than other similar vans. See
>
> http://camping.elliott.googlepages.com/poormileage
>
> to see what I've learned so far about this 1.9L 1984 auto transmission
> with only 75,000 miles on it.
>
> One oddness I've found is that both plugs on the passenger side indicate
> lean condition, while the plugs on driver's side indicate rich condition.
> Where could such an asymmetry come from?
>
> There are NO visible signs of air leaks. The intake runners don't have any
> cracks, are tightened well against heads; the plenum/runner sleeves are
> clean and intact; and there are NO cracks in the exhaust bits that might
> cause a false-lean reading at the O2 sensor -- this is a southern
> California car and we outlawed snow and salt in 1932.
>
> This lateral mixture imbalance has me quite puzzled. I am getting little
> fret marks between my eyebrows! I'm dumping in a buttload of Techron
> injector cleaner in case the injectors on the lean side are packed up and
> the ECU is overcompensating by running #3 and #4 rich.
>
> But . . . and but, the overall mix at the O2 sensor indicates /lean/ on
> the highway, oddly (see
> http://camping.elliott.googlepages.com/poormileage).
>
> I am replacing the O2 sensor on Monday. Because.
>
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>