strange problem

hi all i have been saving to get the dmf and clutch done on the car as flywheel was beginning to rattle on idle.Whilst on my way up the road the car began to hesitate badly like when you run out of fuel type hesitation,i rolled into a layby and it cut out then as i tried to restart it there was clouds of smoke from exhaust and wouldnt fire up.Rac were called sometime later, he turned the key and it went then two miles down the road the hesitation began again with lots more smoke and eventually it cut out then wouldnt fire up again.He diagnosed a sticky injector and possibly the timing chain was a bit slack.Has anyone else had these symptoms? if so what did it turn out to be? regards sean