1991 ISUZU STYLUS Vehicle Speed Control Problems

THE CAR SURGES WITHOUT WARNING WHEN IDLING. THIS APPEARS SPORADICALLY AND UNPREDICTABLY. IF THE CLUTCH IS ENGAGED, THE CAR WILL LURCH FORWARD AND STALL. IF NOT ENGAGED, THEN THE ENGINE SUDDENLY REV'S VERY HIGH. AT TIMES THE ENGINE IDLES HIGH FROM START CONSISTENTLY FOR 5 OR MORE MINUTES AFTER STARTING, REGARDLESS OF WHETHER THE CLUTCH IS ENGAGED OR NOT. WHEN THE ENGINE REVS HIGH, THE CAR LURCHES AND DRIVES ERRATICALLY WHEN IN MOTION. I HAVE BEEN TOLD BY OTHER ISUZU STYLUS OWNERS WHO REPORT SIMILAR PROBLEMS THAT THIS IS AN ECU ISSUE AND THAT THE PART SHOULD BE REPLACED, AS IT IS A DESIGN FAULT.

MY REGULAR MECHANIC INDICATED THAT THE PROBLEM WAS ELECTRICAL. SO I TOOK THE CAR TO A DEALERSHIP. THEY INDICATED THAT THEY COULDN'T FIND A PROBLEM, BUT ON THE WAY HOME IT STALLED AGAIN. WHEN I SLOW DOWN OR COME TO A STOP THE CAR WILL SHAKE AND IDLE HIGH AND THEN STALL. IF I PRESS THE GAS AND KEEP THE CAR REVED UP IT WILL EVENTUALLY RETURN TO REGULAR IDLE, BUT SOMETIMES STILL STALLS.*AK

THE CONCERN WE ALL HAVE IS WITH THE UNPREDICTABLE ERRATIC IDLE. WHILE SITTING AT A STOP, THE RPMS WILL JUMP FROM A STEADY 900 TO BETWEEN 2000-3000 UNEXPECTEDLY. THERE IS NO WARNING. I HAVE HAD TWO 90+ ISUZU CARS AND BOTH HAVE HAD THE SAME SYMPTOMS. AS THEY WERE BOTH MANUAL TRANSMISSIONS, I WAS NOT AS CONCERNED WITH THE POSSIBLE SIDE EFFECTS OF THIS SINCE WHEN IT WOULD OCCUR I WOULD EITHER HAVE THE PARKING BRAKE ON AND BE IN NEUTRAL, OR THE CLUTCH WOULD BE ENGAGED. OUR MAJOR CONCERN IS WITH HOW THIS AFFECTS THE AUTOMATIC TRANSMISSION VEHICLES. THE VERY POPULAR GEO STORM IS INCLUED IN THIS GROUP OF CARS, SINCE IT SHARES THE ENGINE AND ELECTRICAL SYSTEM OF THE ISUZUS IN QUESTION. THERE HAVE BEEN CONCERNED NOTES FROM OWNERS OF THESE CARS WITH THE AUTO TRANSMISSIONS WHO HAVE BEEN SITTING AT A LIGHT WHEN THIS WOULD OCCUR AND...

I EXPERIENCE UNCONTROLLABLE ENGINE IDLE SPEED WHICH CAUSES DIFFICULTY IN MODULATING ACCELERATION WHEN LEAVING A STOP. THIS HAS THE POTENTIAL FO CAUSING UNAVOIDABLE COLLISIONS WITH OTHER VEHICLES OR PEDESTRIANS.*AK