vauxhall astra... need help?

Hi I have a vauxhall astra 2.0 cddi diesel
My mum bought the car as a non runner on the assumption it only needed a new battery, turns out the injector seals had gone they have now been replaced but its still not working. we put fuel directly into the hose from the filter that goes to the pump and it squirted out the injectors as it should but it wont bring any fuel up from the tank to the filter but its sucking. what could be the problem