Replaced fuel sending unit (with proper sock) due to original not working. Replaced fuel lines from lift pump to fuel sending unit. Also replaced lift pump and OPS.

Now: engine will only stay running with fuel filter air bleed valve opened. Lift pump running normal. Fuel coming out of air bleed valve while engine running looks sort of 'foamy'. If I close air bleed valve, engine seems to run fuel out of FFM and stalls. After engine stalls, when I open air bleed valve a burst of air comes out. If I leave air bleed valve open, engine restarts and runs normal. Also, opened water drain valve and good clear fuel comes out and engine stalls.

I knew I was introducing a lot of air into system replacing fuel lines, but it's obvious something else is going on. Fuel tank started about 3/8 fuel, now with all attempts to bleed air down to about 1/4. I rechecked all connections that were made during parts replacement and everything is tight.