I have just sold my US spec 16V. However, it sounds to me (with my limited knowledge) that you car is running very rich on idle. On the US cars there is an adjustment just behind the airbox that controls CO at idle. When I adjusted the screw too much, so the idle was too rich, on start up, with the cold start engaged, the engine would hunt up and down, until the engine warmed to normal operating temperature. I know that on US spec cars the CO adjustment can control alot of the problems from the injection systems.
The best guy to talk to is Adrian Eckenrod, he knows his stuff, I think his email is RAE190@mindspring.com