CRDI SPORGE ACTICE pressure regulatory valve

Greetings to all, can you help me? The problem is as follows: the scanner indicates that it is the pressure regulatory valve, in 3 technical service workshops they have reviewed it, we have changed it but continues with the problem. The car turns on, when it is cold, it goes out immediately, after turning it on again, by several occasions and when it is heated, it remains on, but when accelerating it it goes out.
I've been with the workshop car in workshop and not find a solution.
How do you have the same problem? I thank you in advance.
Jorge Paredes