Non starting after cutting out

a few months back started getting loss of power whilst driving ,had to remove key lock doors from outside passenger door then jumpin to restart ,then happened more often ,now since then intermitent starting probs ,its not ecu,starter or battery all checked been diagnostics checked come back with no probs found ,now it wont start at all turning over etc but not firing ,thinking maybe immobiliser etc ,doors lock from paSSENGER SIDE DRIVERS DOOR DOSENT LOCK AT ALL NOW ,BURING MY BRAIN OUT NOW