Have you checked the LIVE 12volts at the injectors ?, if they don't get this they won't open, hence no fuel, the rail is fed by the same supply that goes to the fuel pump relay to energise it, but you may have a broken wire/bad connection somewhere stopping the live feed at the rails, the negative pulsed supply from the ecu is there, so that's good just check the live now, you can always put a live to any of the injectors LIVE supply side and it will light up all 4 of them, then at least you'd know you were on the right track.
tabetha