YOU MAY JUST HAVE A BAD ENG WIRING HARNESS, NEXT TIME IT FAILS TO START , I AM ASSUMING IT IS TURNING OVER BUT WILL NOT FIRE, HAVE SOME ONE TURN THE KEY TO TRY AND START THE ENG WHILE YOU WIGGLE THE HARNESS AROUND ON THE FT OF THE ENG IN AND AROUND WHERE THE HARNESS GOES AROUND THE CORNER OF THE HEAD ,(VLV CVR) EITHER SIDE OF THE ENG CAN CAUSE THIS , THE HARNESS IS INSTALLED A LITTLE TOO TIGHT AROUND THIS AREA AND IT CAUSES THE WIRES INSIDE TO GET BROKEN AFTER TIME, NOT A BIT UNCOMMON . JERRY OH BE VERY CARE FULL DOING THIS WITH YOUR HANDS AROUND THE FAN, IF YOU HIT THE RIGHT WIRE WHILE SOMEONE IS CRANKING, IT COULD FIRE INSTANTLY SO BE CAREFULL .