It did it again tonight. It was warm so no glow plugs. It splutters after about 10 seconds of starting but only for about 5 seconds, it puffs a bit of blue smoke while it's spluttering too. I think it's possibly oil being drawn in, which explains the slight delay.It is possible that the hiccup at startup is an injector showing early signs of failure.
Mike
It only seems to do the splutter thing if the plugs aren't used. It's fine starting from cold, which is odd.