furballi

Thanks for the tip. I checked the throttle control motor, throttle position sensor, and pedal position sensor of the 1999 GS300 per your *pdf link in this thread. Only the pedal position sensor was out of spec...min of 1640 ohm vs. 1532 ohm actual. I have yet to calibrate the throttle position sensor because I don't know the correct setting voltage for the 1999 GS300...have read it's either 0.65VDC or 0.72-0.74VDC. Perhaps someone can chime in with the correct value. The car would usually run okay as long as I gently apply the gas while keeping the engine speed to less than 2000 rpm. Fast stabbling of the accelerator pedal would often cause a loss control of the throttle plate in the throttle body (engine speed drop to idle or a few quick revs up to about 2500 rpm). Flooring the gas will allow the mechanical throttle cable to slightly open the throttle plate, allowing the car to crawl around 30 mph. I also hear a slight buzzing sound from the throttle control motor when I turn the switch to ON without starting the engine. The noise becomes louder once I get any kind of slight movement in the pedal position sensor. This tells me that the pedal position sensor is throwing out some strange signal. Does anyone know which output wires on the pedal position sensor can be connected to an oscilloscope so that I can see if this thing is operating properly during normal driving condition? I hoping I can tap into these wires at the ECU inside the car. BTW, your link was for the throttle position sensor. I can get this item at Autozone. The part that I need to secure is the pedal position sensor that is locate on the opposite side of the throttle position sensor (near the firewall).

Anyone know of a good source for the Pedal Position and Throttle Position Sensors for a 1999 GS300 that doesn't cost a mint? I will be testing them this weekend. TIA, F