Well I think the pump is original to the engine, which was new in 1987 155k miles ago! I havent had the pump apart as I bought a spare off ebay to tinker with, but havent touched that yet either and currently based on what your saying I am tempted to stick that in just to see what happens!
At the moment due to so many wheels and brakes in my workshop I have no space to strip down the pump sensibly. I suppose the options I have is stick a N/A set of injectors in, use the N/A pump as well giving me an ecodiesel, or just swapping my current pump with an ebay one which I wanted to rebuild first.
One problem I do have is actually timing the pump up because I cant get a DTi in the timing hole of the back of this pump. and its a hell of a job even getting to it all as its a bit tight in my bus. I have been wondering if maybe the fuel pump is leaking from somewhere I cant see.
I guess maybe I could swap pumps and mark everything right up best I can, matched pump to pump and see what the difference is in the way it runs, if nothing its either really bad timing, knackered injectors or 2 knackered pumps.
I think maybe my plan c/D should be to put both N/A injectors and pump in as I Know they are all ok, might lose a little power mind.