I don't know how I can check the actual pressure from the LP pump, I had replaced the fuel filter about 2 weeks before my first post, but I did disconnect the supply to the HP pump and ran the diesel into a empty 2 litre plastic milk bottle and there was no air in the fuel and it seemed to be flowing pretty quickly as I switched on the Ignition and listened for the pump and after what seemed like a few moments when I got to the engine bay it was 1/4 to 1/3 full so checked for air in the flow saw none so went back and switched off.
I appreciate that this is only volume and that it could still be at the the incorrect pressure, however it was running perfectly well (all be it the misting of diesel from the base of the injector) before I removed the injectors.
I have tried the cam sensor in the freezer trick to no avail, which I suppose may or may not rule that out, I have not even looked at the crank sensor or the regulator on the HP pump come to that.
I keep wondering if it is anything that I have done somehow when removing and cleaning the injectors, but I have had the injectors apart twice now and all the internal components are in there and in the correct order, I was also very careful to ensure that the tiny disc was sitting flat and not at a angle when re assembling.
I don't know if there is any way of checking the cam sensor or the crank sensor with a multi meter, if there is I would be grateful of the being told the correct procedure