car don't start
 

Two day's ago my car stop on a middle of intersection.After towtrack drop my car off my mechanic change fuel pump.When I pick up car it did't start.Today he change fuel hose,and drop my car at my house with message that it wokrs.When I got home car didn't start again.He said that he don't know what is wrong with it.I'm really need help,or my mechanic does.Car was in his shop for 48 hours. I have new 500 engine in it,19800 ml, new battery,alternator, transmission.Any ideas?