i have attached a PDF you need to check any electrical plugs on items 15,17,19 take them off and clean them and also have a look make sure there are no loose or worn though vacuum pipes around item 17
trouble with the system is if you have to dismantle it you need setting and holding tools
i would suggest if you take it anywhere take it to 1320 mini it abit of a drive but they are worth the trip. they know these minis in side out.
you could call them they may be able to help Contact Us
depending on what engine you have the valvetronic motor sometimes fails due to lack of servicing oil changes, the mech gets all slugged up.
this will cause the inlet timing problems
sorry can be much more help its hard to fix when it not in front of me :-(