As the "Docs" already stated you need to find a for want of a better word a real mechanic.

NOT someone with a scanner.

You need to establish some basics like is it sparking? and do the injectors have a pulse?

What's the pulse width?

Questions of that sort.

STOP throwing parts at it,

little chance of the right part hitting and fixing the fault.

Back when there were not fault code readers you checked it had a spark/compression,

checked there was fuel/pressure and so on.

these old school checks though they've been largely forgotten still stand,

and work.

Best advice is find say an older guy who knows his stuff or find your local Bosch technician.

They seem to be better trained/equipped.