If I was working on this car I would be checking the following:
1) fuel rail pressure
It needs to be the right pressure when cranking and again when running. There are also control valves (usually in the pump or on the rail) to control the pressure in the rail which would be worth checking at the same time.
2) scope the injectors to check they are all opening and closing as they should be.
This rules out ECU and wiring faults to do with the injectors.
3) scope crank and cam posistion sensons.
Without timing information if wont inject at the right time.
4) measure the leak off from each injector
If all are equal then its not a faulty injector - as the car ran before it should run again!
Running a car up on easy start is in no way a method of diagnosis sadly!
Alex