I have just bought a 2005 130 tdci mondeo ghia x and when acclerating over 3000 rpm the coil light comes on and either cuts out or goes into limp mode. i have checked the fault codes and they are P0401 egr and P0251 injection pump a circuit malfunction. The pervious owner had the injectors replaced and i have checked the mass air flow wires and they are clean and i have removed the egr and cleaned all the carbon from that but still the fault occors . any help would be great.

I think you answered your own question.
Injector pump is not keeping up with the job.
I'd see a diesel expert to check the pump and injectors too.

the two common causes for P0251 are a blocked fuel filter or an injector leaking-off excessive amounts of fuel, i would get these checked before going for the expensive pump, as stoney said a good diesel expert should find whats wrong.

Seeing as your getting an egr and fueling fault I would suggest the egr to inter cooler boost pipe is split, I would recommend removing it an checking it carefully