Ford focus tdci 1.6 2005

[kledi]

Hello im havint a problem those days ... after first start of the car it turn on but after few seconds will cut off without any strange noise noo smokee nothing .. i try to start it again and will start after a little bit hard but will start after no problemss run good not strange noisy no  any smokee... few days ago i had  those problems too start car and show a message engine system foult ...some oil over my engine.. i send ito garage to clean it he put a gasket and now no more oil .. and he said he one tube was damaged he fix those things i try the car runned very normal i took home... but next day i try it in morning start very fastt and no cutt off .. next day started and cutt of but now i have no message like i said engine system foult .... i started today and cut off i start it again run very well and if i go now to start it again will start and will not cut off ... if i go tomorrow the car will start and cutt .... any ideas whats that could bee .....  i have changed fuel filter .. and clean fuel tank before 4.000 km ago