Mine was doing exactly the same thing. Same motor! Check the engine temp sensor as this will tell the computer the motor is cold and run it rich. They are cheap to replace,or you can test their resistance etc. I also replaced the 2 injectors as they were filthy. I have also now had them professionally cleaned and keep them as a spare.
My money is on the temp sensor. It is the 2 wire unit out the top of the head near the throttle body sensor. Also when you replace it check inside the hole / head as mine also had a huge build up of muck arround the sensor which would not have helped either.