93 civic engine swap

I swapped my stock D15 engine for a D16z, y engine is sputtering now is it the idle controller or is it the ecu. I am not sure when my engine was swapped dat he changed the ecu.
please help

first which model car do you have.. unless you have a cx the ecu shouldnt matter. also what do you mean idle controller. make sure the timing is correct.. and does it have a check engine light on??