coils probs, anyone a autospark??

my mk3 gti(oops) will not start, its not sparking, when i did a coil test there was nothing untill i turned the key off, it then gave a cracking blue spark, anyone know why this happens? also , anyone got primary and secondry winding figures for me to test this coil? cheers

ps. sorry for taking a mk3gti into forum but at witts end. ops:

Nothing is switching the coil supply off, so when you turn the ignition off, it discharges. Look to the crank signal into the ecu.