MICROTECH LT16 1JZGTE - WEIRD FUEL CUT AT 5500 RPM

A friend of mine just recently swapped a 1JZ-GTE into his Silvia chassis, problem arises during tuning when the engine had fuel cut @5500 RPM, i'm rather new to MICROTECH ECU ang tuning in general. Any Microtech or EFI Tuning gurus that can shed some light on this problem ?

I'd be looking at your rev lim, rev cut and boost cut functions. These are the obvious areas that you can get tripped up. Alternatively you may have some trigger issues that are causing your apparent cut.