Stock CIS, running out of gas at 2 bar?

["Scott M." <scottmo@teleport.com>]

I was doing some testing yesterday on my 89 200TQ where I
measured the voltage output from the CIS Air-flow plate
potentiometer (used for fuel mileage calculation). This
potentiometer (variable resistor) tells the dash computer
how high the air-flow plate rises while you are driving. 

With the ign. key on and the air flow plate pushed up by
hand to the top of its travel (max air flow) the voltage
output was 4.465 V. 

At idle the voltage output was 0.135 V, I routed the
DMM/cables inside the car and went for a test drive. (~60
degree F). I drove the car in 3rd gear at full throttle all
the way to redline on a flat road. I had the DMM set to
record Min/Max voltages and a boost transducer/DMM to
record the max boost. The air-flow plate rose up until the
voltage read 4.216. Max boost recorded was 1.79 bar. If we
assume a linear relationship, the air flow plate was at
~94% of its travel. I would imagine that there are a few
people running around who are pushing their air flow plates
to 100%. I don't know if the fuel distributor plunger
continues to output more fuel all the way to the top of the
plate travel or if it tops out earlier.

The later dual knock sensor MC engine does show a different
air flow sensor plate assembly than what was used on the
early MC engine (86-88 5000TQ, 89 200TQ). The fuel
distributor heads between the early and late MC engines
have the same Bosch part number although the replacement
rebuilt head for the late MC does not have the internal
fuel pressure regulator plunger installed. 
I remember Ned quoting that the stock fuel injection was
good to 300-325 HP, at this point, I think that figure may
need to be reduced a bit.

Cheers
Scott M.