COMPONENT (DIODE) ON 60 PIN PCM HAS A SHORT CAUSING INJECTOR NUMBER 6 TO STICK WIDE OPEN. RESULT IS A CYLINDER COMPRESSING FUEL WHICH CAN LEAD TO EXPLOSION, ALSO RAW FUEL ESCAPING OUT OF THE TAIL PIPE AND LARGE AMOUNTS OF SMOKE. GASOLINE PULLS THE OIL OFF OF CYLINDER WALL CAUSING EXCESSIVE FRICTION AND ENGINE DAMAGE ALONG WITH CATALYTIC CONVERTER DAMAGE. IF REAR ENDED WHEN INJECTOR IS STICKING OPEN COULD CAUSE EXPLOSION OR FIRE! I HAVE CONFIRMED THIS ON 3 OTHER 93-95 GRAND CHEROKEE OBD I MODELS AS WELL. JEEP WAS IDLING NEAR SOMEONE WELDING AND THE INJECTOR STUCK OPEN AND STARTED A FIRE. FIRE WAS EXSTINGUISHED IMMEDIATELY WITH DIRT AND WATER. NO PHYSICAL DAMAGES OCCURRED JUST A SCARE. I MOVED INJECTOR 6 PLUG TO 8, THEN 8 STUCK OPEN, UPON PUTTING PRESSURE ON THE COMPUTER CONNECTOR I REALIZED THE INJECTOR WOULD OPERATE NORMALLY AGAIN. BEEN HAPPENING FOR MONTHS, JUST NOW FOUND THE ROOT CAUSE. WILL UPLOAD PICS LATER IF IT WILL LET ME. I CAN SET FIRE TO THE GROUND WHERE THE TAILPIPE IS WHEN INJECTOR IS STUCK OPEN.