I have a car ,ford fiesta 2010 ,1.4tdci, the motor stop and dont start again , i just repalce the injectors ,rail sensor ,high fuel pump regulator ,new filter..and still get error  "Fuel pressure low" and the engine dont want to start , only with spray start but in 2 sec died again

All of that work without any concrete evidence of faults or... (you don't tell us why it was all done)?

If that is the only fault code (?), my first point would be to get live data of fuel rail pressures (demanded and actual) plus, first, the simple check of looking for any air in the fuel lines due to faulty connections/air leaks, cracked filter housing etc.

Your Easy Start test MAY suggest that everything mechanically is OK and it is, indeed a fuel issue?

1 hour ago, Shearers said:

All of that work without any concrete evidence of faults or... (you don't tell us why it was all done)?

If that is the only fault code (?), my first point would be to get live data of fuel rail pressures (demanded and actual) plus, first, the simple check of looking for any air in the fuel lines due to faulty connections/air leaks, cracked filter housing etc.

Your Easy Start test MAY suggest that everything mechanically is OK and it is, indeed a fuel issue?

The mhecanic change everyhing, i dont work on my own , he told me what he need to do , i say ok ,if u can repair let s do it 

1 hour ago, Bogdan Munteanu said:

if u can repair let s do it 

You did say "I just replace" so, I'd take a step back and do (or get someone to do) some serious checking and diagnostics as he has spent presumably a lot of your money on expensive parts and you still have a fault (however, we don't know the full history)

My previous suggestions still apply (and, hopefully others can make their suggestions that can be checked)?