s14 si

under boost at 6000 rpm my 99 si cuts off, it will not let me go past 6grand, if i dont boost it the car wont cut off. the car will do this at 1 pound and at 10 pounds the amount of boost does not mater, and i have no check light. these are the things i have all ready played with,

map sensor bypass with check valves and missing link
different ecu
smaller spark gap
fuel regulator
fmu
310 injectors
timing
the only thing that could be doing this is my distributer, it could be freaking out under load or a bad ground, if u can figure this out i will pay money!!!