Intermittent Cold Start Problems with 1.9 TDI Sport

Hi all,

I have an 06 Polo 1.9TDI Sport which has developed an interesting intermittent problem. Sometimes it starts cold and sometimes it doesn't.

Essentially if left overnight it might start immediately and run fine or it might briefly fire for like half a second and then die, then it will only start if I hold down the accelerator pedal and crank repeatedly for about 30 seconds or more. In this case it slowly splutters into life and runs fine.

It sounds like glow plugs but the intermittent nature of it makes me suspect something else. It was stood for almost a year, hardly used and had a new just throttle body in May, was hardly driven between then and now but did it for the first time just before I replaced the the EGR valve cambelt and oil. It's still doing it.

If there were a pattern it seems like the trouble starting has only occurred after I've driven it the day before for more than about half an hour. But this is pure guesswork correlation at present.

Any thoughts or ideas very welcome.

Thanks, Jamie.