Just after swapping a b16a into a civic and its idling very rough, hunting and miss firing and this persists in the lower rev range, once in vtec at WOT it runs fine. Took the plugs out and there black so looks like its running rich or not burning the fuel correctly. Any ideas to where I should start looking to overcome this problem?

 

Anyone?

 

Not enough info.

What year Civic did you swap the engine into? What ECU are you using? Any CELs? That would be a start so maybe people could help you.