Please help A7 not starting

[vw754]

3.0 TDI 2013 done 130k full service history.
Car cut out and would not start,no fault codes .....so I tried with easy start,car started and was running at idle for around 5 minutes,I revved it and it revved as normal but I could feel like it had a misfire,I tried drive it,it drove literally 5 seconds,and it cut off, would not start again..... plugged vcds in and it came up with 1 fault only....5215 fuel rail/system pressure too low.
Any ideas what it could be?
Car did feel like it was misfiring at idle last week,so had fuel filter and a service,but didn't make any difference.

 

[billgatese30]

Fuel pump could be failing and not delivering enough pressure, or there may be a pressure sensor which is failing and giving a bad signal. Alternatively it could be blocked/failing injectors which can't deliver enough fuel. None of these are a 30 second check and may take a bit of effort to diagnose.