im sorry, seems like you haveing the worst luck ever.
yeah also check for voltage, and see what you are getting and diff. points(refer to the fac. manual on the voltage drop spec.). Also the injector might no be closing or getting stuck open, so see if anyone local has some sidefeeds you can borrow(i think stock DSM injectors are side feeds and are 440's).
<-Put an EJ20G into a GC, and trust me that thing will make you grin every time you beat an STi or an EVO
. Also what i have noticed, is dont let the car go over 1bar of boost, if you can keep the boost at 14.0 that will be the best. My friends car would start hitting fuel cut on anything over a bar.(this is the stock ECU and everything else all stock, on a ej20g)