99 wf festiva 1300 3b engine rebuild non starter series two

[FeistyFiesta]

If it was running before, it's unlikely an injector/s has gone bad suddenly.
What you might be experiencing is some more likely something like an air/airpocket or forgetting an earth on the harness.
It would be better for you to test your injectors at the connector with a Noid led light.
That's all assuming you're on the right path with the fuel being the issue...

Have you started it on aerosols? Does it run/rev okay with them?