OWNER OF 2005 TOYOTA SIENNA LE MINIVAN PURCHASED IN DECEMBER 2004. 1. NOTICED THAT THIS PROBLEM STARTED TO OCCUR OVER THE LAST TWO MONTHS AND THE OCCURRENCE HAS INCREASED IN FREQUENCY. 2. DESCRIPTION OF PROBLEM: WHEN DEPRESSING THE ACCELERATOR PEDAL TO ACCELERATE FROM A STOP, THE THROTTLE WILL OCCASIONALLY FAIL TO RESPOND TO THE INITIAL PRESSURE BEING APPLIED TO THE PEDAL. CONTINUING TO DEPRESS, OR APPLYING ADDITIONAL PRESSURE TO, THE ACCELERATOR PEDAL WILL EVENTUALLY CAUSE THE THROTTLE ON THE ENGINE TO ENGAGE AND THIS RESULTS IN AN UNANTICIPATED SURGE IN ENGINE OUTPUT AND ACCELERATION. MY CONCERN IS THAT THIS UNANTICIPATED ENGINE SURGE AND ACCELERATION COULD LEAD TO AND/OR CAUSE A TRAFFIC ACCIDENT. 3. BROUGHT THIS PROBLEM/ISSUE TO THE ATTENTION OF THE SERVICE DEPARTMENT AT LOMBARD TOYOTA (LOMBARD, ILLINOIS). SPOKE WITH TWO DIFFERENT SERVICE WRITERS AT LOMBARD TOYOTA AND THEY BOTH MENTIONED THAT THIS WAS A KNOWN ISSUE BY BOTH TOYOTA AND THE DEALERSHIP. LOMBARD TOYOTA MENTIONED THAT THEY ARE CURRENTLY UNABLE TO DO ANYTHING TO CORRECT THIS PROBLEM/ISSUE AT THIS TIME.