VEHICLE INFREQUENTLY SURGES WHEN INITIALLY PRESSING DOWN ON THE GAS PEDAL. ALSO IT HAPPENS WHEN DRIVING AND PULLING UP BEHIND VEHICLES AT STOP SIGNS OR TRAFFIC LIGHTS. IT CAUSED AN ACCIDENT WHEN TRYING TO PARK IN A TIGHT SPOT. SURGE WHEN TRYING TO EASE FORWARD CAUSED VEHICLE TO RUN ONTO STONE WALL. NOT AN ACCIDENT INVOLVING AN PERSONAL INJURY BUT POTENTIAL IS THERE FOR A SERIOUS ACCIDENT. UNRELIABLE ACCELERATION IS A POTENTIALLY DANGEROUS ISSUE. A SECOND OCCASION WAS IN TRAFFIC AFTER MERGING OFF A FREEWAY. SEVERAL CARS WERE WAITING AT STOP SIGN. AS EACH PULLED OUT WE ALL EASED UP. WHEN I TRIED TO EASE UP IT SURGED ON ME AND ALMOST PUT ME INTO REAR OF CAR IN FRONT OF ME.