I bought an Accel 300+ ignition from a guy at the track. I got it home and put it on and the car runs a little rough in idle and driving in the 1500-3000 rpm range. The guy told me how to install it. But I do have one question, there is a green wire on the igniton box that isn't being used. The guy told me he didn't know what is does or where it goes. Could this be my problem?