Ahab Needs Help

["Lawson, Dave" <dlawson@ball.com>]

>
I'm hoping for a little more direction before the Great 
White Whale goes to my mechanic this week.. 
        Symptom: When car(91 200q) nears full boost, power 
suddenly drops off substantially and the motor runs quite 
roughly. Boost also drops. If I back off on the gas, all is 
well again.
        Plugs have been replaced, IC to TB hose replaced, bypass 
valve is recent, hoses have been inspected closely (yup, I 
know I still need to pressure test). 
        Suggestions include: frequency valve, plug wires, 
cap/rotor, static timing, pull fault codes. 
        If anyone has any more helpful ideas, I'm all ears.
Thanks to those who have contributed thus far.
>

Sounds like a bad mass airflow sensor. Had direct experience 
with a friends car, and have heard of a few others with this
problem. Low boost /easy throttle the car works fine, heavy
boost/full throttle, higher revs, car runs rough.
 
HTH
-
Dave Lawson