[200q20v] Great Acceleration until "Brick Wall"

[Dale McCormack]

Oh wise ones...
While on a modest 100+ mile trip I encountered several instances while
accelerating of "bucking, erratic engine behavior".  This happened both
during "hard" acceleration and occasionally when the cruise control
would attempt to adjust the speed (appx 85 mph, 22 mpg).  The engine
compartment fuel filter has about 5K on it and about 120K on the
engine/vehicle.  I usually run 93 octane and suspect the fuel pump (gas
tank).  No other symptoms of engine problems.  Are there any other
filters that may be restricting fuel flow?

Other than K&N, engine is stock.

TIA,

Dale McCormack
'90 200 tq Avant, chip, coil-overs, et.al.
'91 200 20v tq