Knocking sound from engine

I broke down the other day, loss of power and a big of exhaust smoke. Stop to have a look and it wouldn’t run, it would start but cut out after a couple of seconds.
Rang for recovery and we noticed the swirl flap bar had come off, he then proceeded to take the fuel rail off in the roughest fashion I’ve ever seen, breaking a injector leak off pipe in the process.
After he put a screw in the leak off pipe to stop it spraying all over it ran, but he then revved it and that’s when the awful knocking/rough running started.