[Scruff]

Originally Posted by SilverSurfer

pull the bottom hose off the boost control solenoid (the one that retuns to the air intake with the restrictor in it) and see what that does
http://www.polarperformance.co.uk/boostsolenoid.html

I'd best tie myself in so i don't end up putting my face through the windscreen. The problem is that its not making enough boost though, not too much but i'll give it a go. I have a spare set of hoses for that so maybe i can swap them all over anyway. One might be gunked up? Problem is that the cars behaving itself at the moment so i really need to wait until it goes wrong again.

I'll have a look for an actuator too. Could that be a cause? I don't know exactly what the actuator does but as i understand, it pulls a little arm and makes boost get bigger. Could the little arm be seized?