Injector pump issues ???

Hi all,
I have just acquired a '96 300 tdi manual i think the injector pump is duff, any thoughts much appreciated:
Going to start it in a morning it fires instantly and runs as sweet as a nut, if you give it full throttle nothing happens!, after ticking over for 3 or 4 mins it will rev but very laboured and misfires as it does.
The tank has been cleaned out, the sedimenter replaced, new flow and return fuel lines, new filter checked filter housing for cracks or other problems, new genuine LR lift pump.
Timing case off checked static timing
The only thing i can see that makes me think pump is that there is hanging from the loom a blue plug which i assume went to the EGR control, this pump doesnt have egr.

So is it the wrong pump or are the non fly by wire pumps interchangeable
Opinion seems to be divided whether they are or not, does any one have a definitive answer

Thanks in advance for help and suggestions

Phil

Can you confirm the shut off solonoid is working correctly?

my first job would be to foit a clear plastic pipe in the line from filter to front banjo bolt on injector pump to check good clean flow with no air , you can fit non edc pumps to edc engine as long as you fit pedal assembly ,egr doesnt matter whether its plugged in or not or whether you have it or not