High pressure fuel pump in 159 2.2

[mARc]

Hi all,
This is my first post on this forum so excuse me if this subject has already been covered in previous posts.
My 2009 159 JTS Ti 2.2 is playing funny buggers with me at the moment. I'll list some of the issues that I've found over the last 12mths or so.
- Hard cold mornings starts, usually 2 attempts
- Misfire or not revving cleanly between 3k-4k RPMs occasionally (usually when warm) then, occasionally flashing the engine management light for 20-30 secs and then comes good.
- Poor fuel economy currently sitting at 15.6/100Km, fully aware that they are not very economical engines but 15.6!
My mechanics, whom I trust, are saying it's most likely the high pressure fuel pump however I can't find anything on any forums worldwide that this has been an issue, maybe I'm looking on the wrong sites.
Some advice would be greatly appreciated and again sorry if this has already been covered.
Marc.