I have 96 jdm wagon as the turbo kicks in it's as though fuel is being cut off causing stuttering, boost solenoid testing ok and maf sensor cleaned regularly with proper cleaning fluid.
It appears that there is no restrictor pill in the bottom pipe from the boost solenoid as it is easy to blow through ?
And if it's any help it runs mildly better with a Hks induction kit instead of the standard air box set up which I am told is better than hks kit!???

 

Your describing how any scoob runs when you have a big boost leak as soon as the turbo kicks in. You need to check all the boost piping from the turbo outlet to the intercooler and on to the throttle body. Also check the pipe that goes from the bleed nipple at the front of the turbo to the boost control solenoid. Check there are no leaks from the air bypass valve (intercooler dump valvle).

 

Ok cheers