well my bb is in and when i installed JTW ECU it runs super rich mad black smoke when i hit the gass hard with stock ecu it's fine ??? what to do???

Hey this is kinda off topic, but maybe not. What wiring harness did you use? And the stcok BB ecu ran fine right? If i follow correctly...

What ECU are you calling the stock, USDM SR20DE ECU or the JDM SR20DET ECU when it ran fine and if you were running the JDM SR20DET ECU were you also running the USDM MAF sensor and O2 sensor or the JDM MAF and O2 sensor?