or being to hot burning up the metal

To add a little here, if the porosity is in the root pass only and not in any of the fills or cap then you can rule out some of the potential problems. We recently ran into a rash of this problem. The welders wanted to blame the electrodes, inspectors wanted to blame the welders. I ran some test on sections cut from that line and narrowed it down to inadequate cleaning of the inside of the pipe. They were trying to clean the inside with a file - 4" pipe, .219 wt - heavy oxidation on inner wall. I equiped them with die grinders, cleaned 1/4 in. back. Problem gone. Line initially had 18 girth welds, 16 rejected by x-ray for porosity in the root before job was stopped. This is not to say you are not experiencing other problems as stated, i.e. long arc..too much current...just something to consider.