Really scaring me. Happened a few months ago but went away and now its back. Only happens under acceleration. Makes the steering wheel wobble too http://i1322.photobucket.com/albums/u578/Ollie_Haynes/EFD4CA3A-8098-4561-84D7-AE5E6C9DF92E-18624-00000BC44BCB9EE3_zps4c509949.mp4
check the wire into the igniter next to the king lead plug, my wire from the ecu had exposed wires in and was causing an issue when wet. Bit of electrical tape and its fine