i know mines the injectors simply because first time you try and start it, it takes ages due to the excess fuel in cylinders once this is burned off it eventually starts.
if as soon as it catches i turn the ignition off, then start it again, it will start on the first turn.
just pull the injector out and stick it in a jamjar, start the car on 3 cylinders then turn it off, after 7 secs (i think) there should be no more fuel dripping out the injector.