Peugeot 306 hdi non starter but starts with easy start ?

Hi,

I have a peugeot 306 HDI 2 weeks ago i was on my way home it cut out and it wouldn't start, since then ive had an AA guy look at it and we have seen that there is fuel going to fuel filter from tank, also my friend has checked that there is pressure going to the common rail (my friend is a mechanic) ive thought about crank sensor as the car starts and runs when use of easy start, you have to rev it for 5 mins as if you dont it will cut out.

My friend seems to think it fuel pressure sensor has anybody got any ideas????