disco 1 300tdi loss of power and ticking from diesel injector pump

Hi all can anyone help on diagnosis.
yesterday i had a sudden power loss, wont pull over 2500 rpm uphill, also a loud ticking from diesel injector pump, im thinking something has gone inside the pump, any advise would be apreciated before i take the pump off and get it reconditioned.
thanks
Dave

Fuel filter, sedimenter or lift pump... Or any combination of the three!

I'm sure I read on here a little while ago that the injection pumps make a clicking noise when there is air in the system?