*facepalm*
Aparently I have never seen a recirculating fuel system like that before... So yeah. Problem solved. The missing fuel is back in the tank :P
I'll tinker with it this weekend and see if I can get it going from the tank. I may replace the original pump and do away with the electric one. As it is, I'm going to need to play around with electrical work, and that will be one less thing to worry about.