my peugeot 307 cc convertible starts OK but runs rough for a couple of minutes and cuts out if you try and drive it. Once the engine is warm it runs sweet and is responsive. I've changed the engine temperature sensor and had the throttle body checked. The AA did a diagnostic but found no faults. I've even changed to a lower viscosity oil after a suggestion it might be the hydraulic tappets and changed to a higher grade of petrol in case it's a problem with the injectors but all with no effect. Any ideas?
I still need help to solve this problem