Hi! Im having issue with starting my audi. It has 2.0 common rail diesel engine with bosch injectors and HPFP. I changed the fuel filter and didn't bleed the system. Ait got into fuel feed and it didn't start. After cranking for a while i managed to start the engine, but there was clikcing sound preset when raising RPM's. Diagnosed that it was HPFP pressure regulator valve. Changed it for original part from other car and its no start after that. Its cranking but not fireing. Tried bleeding fuel system 5 times with connecting battery voltage to aux pump and in tank pummp. Vented injector metallic tubes from air. Nothing, no ait anymore in fuel system but still no start. Fuel pressure is low. No fault codes present. Did i fried HPFP or injectors? Any help appreciated.