i am a Noob too all this so don't judge

to start off i have a CRX with aftermarket pistons, rods , camshafts and cams it idles a pretty high around 1000-2000 rpm it bounces around at times i was told the cams could be throwing it off so so its best to get it tuned . so i have two pr4 Ecu's one is obd1 and the other is obd0 i am originally obd0 but i have a obd0 ---> obd1 harness on.
anyway the obd0 pr4 is tuned so i remove the obd1 to obd0 harness and i connected the obd0 pr4 but it didn't start. sounds like it wanted too but didn't. any idea why ?

 

You can't just swap between OBD0 and OBDI without also changing other parts, particularly the distributer.