s13 - s14 engines

[TheOne]

is the ECU the same? or does it have to be changed?.well, i have a 93 240sx, i recently swapped a 95 ka on it.everything is put on, engine starts, idles fine, but when i go full throttle from idling, it backfires then goes fine up in the rpms, if i just press the gas pedal to half then full, it'll be all right, what could the problem be? i changed the MAF once allready cause that was causing bad idle. i first had S13 exhaust cam on it, but then changed it back to stock S14 cams to see if that would stop the backfire, but it didn't. the timing chain was set as seen in JWT cam alignment pics, and the timing was at 20 DEG with a timing light.