no turbo in d12

I started out with low oil pressure. Then I lost turbo boost. Oil pressure in engine read good. The mechanic that looked at it decided it was the egr valve #1. he disconnected it and i had oil pressure back. replace the egr valve and now i have about 17 on the turbo. what else could be the problem.

 

Volvo dealership checked it out and they have determined no fuel pressure. Have checked injectors and still nothing. They are at a loss.

 

They have determined it is the fuel pump. Let's hope this works? No codes showing up on truck or Volvo dealership computer when hooked up.