Starts on the first turn, for a few seconds goes up to 3k revs, then drops the revs down and stalls after 3 seconds of starting. If i rev it a bit to prevent it from stalling then once i let the pedal go it starts hunting up and down and juddering.

Once it's warmed up for a minute or two, it seems fine althrough i can still hear a slight misfire note from the exhaust and it idles a bit rough..

Once going, there's a misfire when i try to accelerate from low revs once it starts building up boost.. if i drive it without accelerating from low revs or taking the boost above 0.5 bar it's absolutely fine.
I thought it was from my blown headers gasket, but im starting to think it's MAF that's playing up, anyone else confirm this for me ? Cheers.

 

Have you checked your spark plugs? Any fault codes ?

 

Well i didnt swap them with another set if thats what you mean, but we did take em out just recently to do a compression check and it drove fine for around 200 miles, then my header gasket cracked and the misfire on the go started, now after another month this new cold starting problem surfaced..
I am going to fix my header gasket tomorow to see if that fixes the driving misfire problem, but now with this new problem i m more inclined to think its more related to the MAF, but i'll do a code check just incase too. You think it might be spark plugs if there are no codes?