is it only at cold start up? all the time when you are idling... try to explain yourself with the utmost details u can.. it will make for an easier response..... what is it idling at when its rough? really low? if so then adjust the idle control screw a bit... get your tps adjusted correctly.. a member of fafracing happens to have the tps analyzer deal... if you want to talk to him his name on here is mizike ...but for now just gimme more details...