Have had this problem since I got the car and it was stock as a rock and its still the same after all these mod's !!! The engine misses with any more than 12psi boost. This week all the following gear went in-
t3/t4, FMIC,PFC,Adj Fuel Reg,Big Fuel pump,z32 afm,new plugs(copper-correct gap) and we tested every coil pack with a known good item. STILL MISSING. It runs like a dream until we go over 12psi. I have been told it could be the crank angle sensor(dry solder joints??) but we ran out of dyno time and crank angle sensors. I hope I have given enough details for some of the SA GURU's to offer some idea's.
Cheers
Stevo