I am having the same problem but only when the temperatures are bellow 0 degrees , more exactly bellow -5 degrees . Starts perfect , then dies or idles bad and dies .Start again works perfect . Did the same thing with the ignition on and off and on again , same problem happened.Also the car when it is cold runs bad,a lot of flat spots ,very ugly feeling . The problem with the cold runs has been solved after the fastchip remap , but the other problem with the start and die I will have let you know when the winter comes

) .Also the fastchip remap increased the idle from 800 to 900-950 or something like that so the car idles better after the remap .