Hi Paul

Can you monitor the misfire counts... most scan tools will show this Im sure... VCDS is fantastic and cheap if you haven't got it already.

Watch the misfire counts and see under what conditions generates the most misfires, then do the relevant tests under these conditions.

Lee mentioned the one he had with only a 1bar pressure difference.... I too have had this a few times.

A cylinder leak down test may help.

Also use the misfire counter if you swap any parts round ie, injectors, coils ect...

WPS is the Daddy for smoking compression faults on these engines.

hth
James