VRS PDI starting problem

Evening all, thank you all in advance for all your constructive replies.

My 57 plate VRS PD estate recently (incidentally after it went in for first variable service and had the PDF upgrade or whatever it was) developed a habit of cutting out and then not starting. Took it into local dealer (Edinburgh) who kept it in over the weekend (had to pay for insurance of hire car even though work was warranted....grrrrrrrrr) and then changed crank sensor. Car now has started twice and run without cutting out however takes 6 or so cranks (used to fire up on the first previously) but worse the whole car shakes like the proverbial defecating canine. I'm planning on letting the garage know of the continued problem but running it for another month and then taking it back in to see if they can find any fault.

Anyone got any ideas, sounds like a fuelling problem to me?

Oh and welcome to me on the forum although been a voyeur for years.