Hundreds of strokes of the primer pump in another attempt to bleed the system did not work, nor did I hear any rattle of the check valve. It still wouldn't start. I took out the check valve (pic) and blew into it and it was not leaking and looked clean enough. I pushed on the ball with a wooden stick and there is spring pressure. Not much to go wrong with a ball and spring. This check valve seals pressure from within the IP (pressure from outside the IP opens it). More later.
Edit: I made a boo boo in the last sentence. After looking at the pic and remembering where I poked the check valve ball from (hole at the end of the bolt), I realize it is pressure from within the IP which opens the check valve.
