Hi Chris

Ahhh yes Chris I think you are correct...
I believe this is the same engine as the pug/cit with variable valve lift.

The throttle flap will remain open under normal operating conditions and the ecu will control the valve lift between 3mm and 9mm under different load conditions.

I think I have got some data and info on this engine at home... I m just wrestling with a Zafira at the min but when I get home ill have a look for you mate.

I believe the engine is designed to have a slight vacuum in the crankcase too.
It's just on VAG with a the throttle flap working in a 'normal' way.... when the breather diaphram splits you have to use both hands to pull the oil cap off.

I don't want to lead you down the wrong path but just a thought for now... could you cause a fault
so that the ECU resorted back to 'normal operation' ie, closing the throttle flap and setting the valves to the maximum lift and see how much vac is in the crank case then?

I believe when the vehicle operates in variable valve lift mode there will be -50mbar vac in the intake.

Ill check for sure later.

James