Starts and then staying rough

[NightSky]

Hi,

Scirocco 2.0tdi starts well but then runs really rough sometime cutting out on idle. It runs slightly better once warmed up but still wouldn't respond to acceleration pedal properly. It did had fuel rail code earlier but now it doesn't come up with any error. Any ideas where to start? Already changed the fuel filter

[Deagol]

Have you considered if the fuel pump is doing its job properly?

I have seen a few members where the car was rough and the solution was connected to the fuel pump side of things.

D

[NightSky]

Hi,

Thanks for the answer.

Sorry, what do you mean side of the things?

[Roy_01]

Check injector fuel quantity deviation in measuring blocks.
HP rail pressure, fuel regulator valve, rail regulator valve etc..

[NightSky]

I have only checked high fuel pressure numbers and they were fine it. It does feel to the extent that system is either clogged up or getting air together with a fuel? Does anyone have any tutorials etc? Would appreciate it that a lot.