NHTSA Complaint #707973 — 1991 GEO STORM

ERRATIC IDLE SPEED THAT REVS AND DROPS WHILE YOU ARE COASTING OR AFTER YOU COME TO A STOP. SOMETIMES IT REVS HIGH INTO THE RPM RANGE ABOVE IDLE SPEED, SOMETIMES IT DROPS SUCH THAT THE ENGINE NEARLY DIES OR DOES DIE. HOVERING IDLE SPEED THAT HANGS AT CRUISING LEVEL WHILE YOU ARE COASTING OR AFTER YOU HAVE COME TO A STOP, USUALLY 2,000-3,000 RPM. SOMETIMES, IF YOU WAIT A WHILE, IT COMES DOWN ON ITS OWN, SOMETIMES IT DOES NOT.HOVERING IDLE SPEED THAT HANGS AT CRUISING LEVEL WHILE YOU ARE COASTING OR AFTER YOU HAVE COME TO A STOP, USUALLY 2,000-3,000 RPM. SOMETIMES, IF YOU WAIT A WHILE, IT COMES DOWN ON ITS OWN, SOMETIMES IT DOES NOT. ISUZU AND GEO HAD IN THE PAST (ONLY WHILE THE CAR WAS UNDER WARRANTY) REPLACED THE ECU TO SOLVE THE PROBLEM. ISUZU AND GEO HAD IN THE PAST (ONLY WHILE THE CAR WAS UNDER WARRANTY) REPLACED THE ECU TO SOLVE THE PROBLEM. IT IS MOST DANGEROUS ON THE AUTOMATIC MODELS BECAUSE THE AUTOMATIC TRANSMISSION USES ENGINE SPEED AS A REFERENCE TO CONTROL THE ENGAGEMENT OF THE TORQUE CONVERTER (IF THE ENGINE SPEED IS ABOVE 900 RPM, THE CAR MOVES FORWARD) SO HOVERING IDLE SPEED IS OF GREATEST HAZARD TO AUTOMATICS. IT IS ALSO A HAZARD FOR MANUAL TRANSMISSION CARS BECAUSE ENGAGING THE ENGINE AT 2,000-3,000 RPM WILL RESULT IN VIOLENT FORWARD MOTION. IT IS MOST DANGEROUS ON THE AUTOMATIC MODELS BECAUSE THE AUTOMATIC TRANSMISSION USES ENGINE SPEED AS A REFERENCE TO CONTROL THE ENGAGEMENT OF THE TORQUE CONVERTER (IF THE ENGINE SPEED IS ABOVE 900 RPM, THE CAR MOVES FORWARD) SO HOVERING IDLE SPEED IS OF GREATEST HAZARD TO AUTOMATICS. IT IS ALSO A HAZARD FOR MANUAL TRANSMISSION CARS BECAUSE ENGAGING THE ENGINE AT 2,000-3,000 RPM WILL RESULT IN VIOLENT FORWARD MOTION.