im new to here and this could possibly be in the wrong section, please move it if it is!!

Any way heres the problem,

fiesta courier 1.8d NA was driving down the road to home and van started kangrooing and eventually wouldnt rev and just ticked over even with pedal fully pressed to floor and eventually cut out, did start again but wouldnt rev and again cut out.

So i replaced the fuel filter, still no avail, filled to the top with diesel still nothing removed all fuel pipes and blew out with an airline, replaced, re-blead and guess what still nothing!! it does fire and runs for a second then cuts out. I pressuerised the fuel tank with an air line and there is fuel all the way through the system right up to the pump, ive removed the injector pipes and also blown them out and replaced but still the problem is there starting and cutting out even if i try and give it full revs, went to the extreme of taking out injector 1 and 2 and there firing ok????

There is a black box at the back of the fuel filter that has a fuel in and out on it with a 2 wire plug going to it whats this could this be the problem??
Im thinking that it could be this black box or a possible fuel pump problem sticking solenoid??

Any ideas or recomendations would be much appreciated!
Thanks
Sol