Look for a vacuum leak, you may have a hose that it loose and sometimes it's seated and everything works and then it gets loose and the problems back. I had this happen to me and it was the large 1/2 hose connected to the intake that wasn't tight. To eliminate vaccume as a possible issue remove the large hose at the intake and cap the intake fitting...does it run any better?
The line coming off of the bottom of the distributer is part of the governor.
Mike B
