I have tried to find in old discussions anything that applies and can't to this point. Have truck running quite well after a few months of headaches. Suddenly it started running super rough when cold started. I can rev it up for a bit and it straightens out. If I disconnect the wire for timing adjustment up by firewall it starts cold just fine. I assume that it has started wildly moving the timing when the wire is connected. I will put timing light on it when cold but i think this must be a common problem. Any help appreciated. Got to go help wife with sheep but will check in later. Sure would appreciate some help. Thank You.