hey guys i have a b16a in my 90 honda civic hatch, lately its been backfiring and when i gear between 2500-3000rpm it kinda surges forward for a second, also at times it'll idle at 750rpm and drop to 680rpm and just bounce around...i have no idea whats causing this, ive checked timing, O2 sensors, TPS, MAP sensor, im running outta ideas...any thoughts????

 

Check your ECU CELs.

 

checked for any air leeks , hoses , air in the cooln't system ?

 

checked all that and everythings fine no leaks anywhere

 

did you try fast idel air control thats what was rond with mine or the iac valve there both by thr tp one is under it and the othe is on the back of the intake mani clean them both and one is spring loaded tightin up the screw all the way and check your idel screw its by you mp vac on the tb