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Re: Re: Fuel Gauge Adjustment

Luis Marques <marques@rtis.ray.com> responded to my note with, in part:

    > For the trip computer, a very narrow but long screwdriver is needed.  
    > I made a special tool from a heavy gauge coat hanger wire, cutting out 
    > an 8-inch section, and grinding one end to resemble a flat blade 
    > screwdriver.  This blade is inserted into the hole through the center 
    > of the shaft described above and used to turn a mini-potentiometer 
    > that is mounted at the back of the instrument panel.  (One could get 
    > to this from below, probably.)  With a full (!) tank, turning the 
    > ignition on while holding the trip computer reset button down and 
    > having the function pointer on miles (or km),should yield the display 
    > of a number specified in the Bentley by model.  (650 for 90 quattros)  
    > The potentiometer is adjusted to make the display show the specified 
    > value.
    People should know that this gauge is actually adjusted using a small
    allen key (~2.5mm).  It only has about 9/10 of a turn of adjustment and
    only adjusts the range function, not the mpg function.  Start by
    adjusting the mpg's and only then worry about the range adjustment.  The
    number that shows up during the adjustment is supposed to be the liters
    of fuel remaining multiplied by 10 - so make sure the tank is full
    before doing any adjustments.

On the unit I repaired, the potentiometer has crossed slots for a screwdriver.  
An Allen wrench would not match it, although it might achieve the desired 
motion.  I presume he is correct for his car, evidently a 4000.

2 x 1988 90q