Starting issue

I have a diesel engine. It does start good sometimes and sometimes it does hard start, problem is that I drove it and cut off and time to start it, it cannot start, I service the fuel pump and the injectors by the way its a common rail pump, still the car not starting, try some gas in the intake but instead of sucking it in it pushing out, smoke is coming out the intake and the dipstick, do not know if it have a timing in the pump, did not see a grove on the pump to say it have to go in back the say way, I just do not know what is the problem.