Start from the MC and work your way out. Crack the lines at the MC and see if you can get flow by pumping the brake. If not, you have your culprit.
If yes, then go to the left front and crack loose the fitting to the brake cylinder. Pump and check for flow. Eliminate each brake line as a culprit since one may be plugged or vapor locked. In any case, you won't get good pressure at the pedal until all of the air is eliminated from the system. Even a little air will cause a spongy pedal. Do you have residual valves? If so, one of them could be stuck open.
The only problem with a one man bleeder, is if you don't draw fluid fast enough, it can flow past a bubble in a brake line instead of drawing it out.
If all else fails, start from scratch.
