civicracer94

I have a eg done a h2b swap. Jdm h23 with b16 trans. Car will start and run fine but after u rev it up or drive it hard it starts idling bad misfires and backfires in the intake. But only on low Rpms after its gets above 2k it picks up and goes .. I have changed the. Dizzy,plugs wires,tps,map all sensors, fpr fuel rail fuel injectors put a new intake gasket ,new throttle body gasket timing is dead on getting 37 psi on fuel pressure running a chipped p28 I have another h2b swapped the parts out with that one and the other car runs fine. I'm stumpped I don't have a clue what else to try. I've searched everywhere. Seems everyone has this problem but no one knows what it is. Help !

rick_rabies

calibrated TPS?
plugs switched?
twist dizzy?
you...ssuuure sure sure your map in ecu is good?
stock h motor?

civicracer94

Switched the plugs,wires , map and ecu. I swapped them to another h2b and the other car runs fine tps has been calibrated I've even switch the tb

h22god

I didn't see you say anything about the timing. Did you check it?

h22god

If that checks out I would think it sounds simular to most vacuum leak / not plumed right swaps.

Also I have worked on these h23a and own one. Did you do the resistor box correctly? These injectors are completely different. Mine has OBD1 h22a injectors. Make sure you did the wiring correct on the resistor box and vacuum leak test it.

h22god

https://hondata.com/techinjectorwiring.html

It also matters what injectors the ecu is saying are in the motor. Independent / saturated
Might want to contact the tune provider.

civicracer94

It's obd2 h23 injectors. Egs don't have the box and don't need it with obd2 injectors. And yes timing it's dead on. Ecu is tune for them

h22god

Fuel vacuum timing are the 3 things that cause backfiring. To little fuel will backfire to much will too,if black stuff is all over the bumper. Vacuum could be wrong or leaking somewhere or maybe you didn't wire the conversion correct on the intake components. Timing can be off and the intake valves are opening to soon and the combustion isn't completely finished so it backfires. That's all I got...
Easiest way is to have a tuner come and see what's going on with it.