Hello I am new to the forums. I need help..! My brother has a civic with zc sohc swap and some mods..! it was running fine till the other day..! it started missing, but it will stop after you hit 4000rpms and has no power till 4000rpms can some please help me....? Thank you for your help

 

welcome to the forum. Check spark plugs, plug wires, distributor. Also fuel pressure at the fuel rail, airfilter. Just a start. ( report findings. he may have already tuned it up)