Passat 140 poor cold start

[low down altea]

For a while now my Passat BKP has had a intermittent cold start issue. Some mornings it will crank into life first turn but sounds sluggish and other mornings it will fire and die but will start on second turn straight away. Car runs fine and starts fine once warm but can still be a bit sluggish to start. I have changed the plugs so that can be ruled out along with temp sensor. I have seen a clip on youtube of a Passat that starts the same as mine and turned out to be the in tank fuel pump. Is there a way of testing the fuel pump as it makes a noise when ignition is on but not sure if its causing fault.

[RichardSEL]

It's the filter in the fuel pump. It's not an independantly changeable item -- from the one I saw when I went to a Golf TDi.
They get gunked up the sides so sometimes allow fuel through, sometimes not enough. You can check fuel pressures in VCDS
but as I'm not a Derv head have never had to to it.

There have been reports too of supermarket soup causing bad firing. But again, me being petrol, no direct experience