Well if its not one thing its another. I replaced the plug wires and that fixed my wide-open, under boost throttle, but now I have a stuttering problem at part throttle under boost.
It will build boost at part throttle, but then start stumbling and stuttering and popping (running rich?). My gut feeling is that either the TPS is not good or my BOV is cycling just enough to vent air. This also happens when I am under boost and then let off the gas slightly. Maybe my BOV spring isn't set hard enough? I am not sure, but this sure is annoying.
You named the two things that would most likely cause this problem. Check the tps and the bov. FWIW, a bunk bov caused this on my '88 TC.