"Ticking" noise on hard throttle

[Dum-Dum]

It's not the injectors you're hearing, although they are the cause, you're hearing a diesel knock, a worn rod allows fuel to leak from the pressure chamber into the control chamber and hold the solenoid open for too long on the pre injection phase, meaning you end up with a larger injection of diesel than required.

I don't think this is the case. I know what diesel knock sounds like from firing a) too much methanol and b) Pure butane down the inlet.

It also doesn't explain why every set of ticking ones I've seen has injector blow by and how replacing the washers underneath them apparently cures the ticking (and also the blow by).