Jonathan,
OK you have a new fuel pump with solenoid installed and
you installed the plug in the bypass / return port for dual line operation
and the solenoid is opening but no fuel to burner???
I am assuming this is a two pipe system, meaning one suction line to fuel pump, and one return / bypass line to tank.
Have you tried bleeding the fuel pump?
Did you get the blue Installation Information sheet with your fuel pump? If so refer to: General Information . ...........Important Information....... If all else fails call me in the morning.