Its a very tricky issue, there are so many things to doubt and its not worth changing all for sake of experimenting. Im sure car computer must be recording fault code, read those codes with diagnostic tool and proceed in precise direction. If you cant find any fault codes doubt things in following order:
Fuses / Relay may be getting heated and loose contact and car stalls.
Check all spark plugs, HT leads, ignition coil and engine oil is fine and not due for service.
Then doubt CKPS (Crank position sensor)
Last doubt and highly unlikely is the fuel filter and or fuel pump.