hey my buddy has a 1jz into his s14, he had tech 2 do his wiring but is having a little bit of a issue upon start up, for the first couple mins or so if i rev it up it runs fine but after it gets up to temp. and i start to rev it, it starts to break up really bad an backfires idle jumps around. i tryed replacing the ignitor map ecu ....I dont know if this could possibly be a wiring issue or maybe his coil packs or possibly his tps can anybody help me out on this i would greatly appreciate any suggestions thanx.....

 

most likely the o2 sensor.

 

check the coil packs to see if theres any cracks in the epoxy, clean them real good and look real close.

im not sure im reading correctly, is the car running map ecu?