rusnak

Since you have the Bentley manual now, you are armed with a lot of information. Did you test the afm (air flow meter) temperature sensor? See if it will run with the oil filler cap removed. Then replace it and see if it will run with the fuel pressure regulator vacuum line disconnected. I am suspecting that the cold mixture is thrown off by something, and when the O2 sensor heats up, and the car enters closed loop, it adjusts the mixture and is fine.