Berlingo van 1.6 hdi 63 plate wont start

[Mk1beast]

Hi . Looking for a little help 
I went out and started my van before going to work this morning, it started as normal as I walked back to the house I heard the van splutter and stall , I tried a couple times to get it to start with no Luck 
I looked on the dash computer fault list and the only fault was Key fob battery, so up to timsons for a new battery after work , came home and tried starting again with no luck , I did try and re sync the key to the van again before I tried 
I have primed the fuel filter with the primer pump and it does have fuel coming to it but still it won’t start 
Any help on this would be very helpful as I’m truly lost on what to try now

[Zion]

The battery does not affect starting or running, it's only used for the door unlocking function. Engine start is controlled by a tiny transponder chip in the key circuit board and that part requires no battery to operate.

You will have to get it scanned by a proper garage system or Diagbox (Citroen software) for fault codes - it could be a failed engine crank sensor, cam sync sensor, fuel pressure regulator, HP pump, fuel injector fault, jumped timing belt...in fact many things.

Generic code readers are not much use on these either before you rush out to Halfords and buy one. Get a good mobile mechanic round to scan it. Or the AA and go from there. Need to know cranking fuel pressure is ok and cam / crank sync is ok along with start authorisation from the immobiliser.