Can an injector pump from a 300Tdi be serviced easily?

Its a little odd sometime, it clicks, the click speed increases with engine speed, not got a clue what it is.

The engine itself it a little unresponsive sometimes, I was also thinking if I could even give it a bit of a clean, when I did my Lucas pump on my 90, it had gunk in it, aswell as getting a good service it got all that removed, but that was done by Lucas.

have you tried a cleaner in the fuel?

Ihad clicking in mine thought it might have been something to do with the injectors or pump etc, just done the head gasket and all the nois is gone!

the IP is not really a diy job. usually get a service exchange unit.
(get a second mortgage).

try the other options first, as suggested.