Nissan Sentra 2002 problem

Hello everyone , I don't know how to start, but I have a fault with my Nissan Sentra 2002 sometimes I failed me when I was in a semaphore went out and then it was hard for him to start, now I arrived a major problem two day ago I was on the road and suddenly went out and did not want to start, then they took him to a workshop and the mechanic said it was the acceleration system and that is why I gave me that problem, now I gave me that problem. Original and put one of Chicote,
I ask you to please as I can verify if your diagnosis is true, I want to check it myself and leave it with its original pieces. Take it with several more mechanics and say the same.
Help me please is urgent

Friend that has the label that the gasoline or pina pump took the shot ... why do I think that? When you say (sometimes I failed me when I was in a semaphor went out and then it was hard for him to start, now I arrived a major problem two day ago was on the road and suddenly went out and did not want to start), of course when he warmed he lost pressure and the fuel stopped reaching the engine, when cooling he worked normally again, and then I burn you ... I send it to check it or change it.