Ok, so have searched all the above issues and not been able to find anyone who's had the same combination of issues as me.
I think the issue is either going to be a boost leak, AAC problem or knackered walbro.
So.. it started a few days ago when I went to pull out of a junction and it bogged down and missed until the revs climbed and it really came on boost. Was fine when on boost above around 3k. Noticed shortly after that the idle was at around 1500rpm and the engine was warm.
Managed to get some time yesterday to check under the bonnet, went through all the boost hoses and couldn't see any obvious issues, so thought i'd start her up and try and listen for anything obvious.
That's when she wouldn't start , quickly noticed the smell of fuel so obviously flooding. Left overnight as it was getting late, and this morning fired after a few turns.... took up the rd, idle still high and quite lumpy while cold.
Got home, turned off for 30 mins, and went to start again... and nothing, just the smell of fuel again.
At first, suspected the Walbro was shot. It's about 8 years old and hasn't covered a lot of miles as the car has spent a good time off the road. But I'm not convinced that would cause the idle to be too high.
I haven't checked the AAC yet, so will tonight... and at the same time clean the MAF.
Is the CAS something that breaks down commonly?
K&N is old and dirty, so i'm going to replace that too.
After some advice really, as to what could cause that combination of problems... until the flooding problem, I was convinced there was a pesky boost leak somewhere.
Spec:
Stage 2, Norris designs Chip, Hybrid T28, Apexi AVCR, FMIC, Walbro, K&N, Oil catch can. Running fine for years, and nothing changed recently.