dave209

I know you posted the manual information a long time ago but if you still have it I could really use a copy. I would appreciate it and you could send it to davison209@mac.com

I have a 99 GS300. A few days ago it started to idle rough and was rough on acceleration. It wasn't showing any codes and the VCS light was NOT on. It just had the rough idle and acceleration. I quit driving it right away. The next day I opened the hood. In perfect timing with the rough idle (Like a miss in the engine) i could hear the sound of what I thought sounded like two pieces of metal hitting one another. I could see the cover on the idle air control motor move, in time with the "miss". I pulled the idle air control motor (it looked fine to me) but I was able to find one online for $200 so I ordered it. I just got it and put it on my car. When I started the car it automatically and instantaneously would rev up to 2400 rpm in a pulsating manor, revving up and down all on it's own. If I pressed on the accelerator it would rev the engine more than the pulsating rev, but the pulsating rev continued. Well, I shut the car off, started it again and it revved at a constant 2200 rpm with not pulsating. When I stepped on the accelerator it did nothing, as if it were completely disconnected. I shut the car off again. Upon starting it for the 3rd time the pulsating revving started again and the accelerator worked again. I should also mention that the check engine light and the VCS lights did come on and I am showing code P0120. I disconnected the battery for a few minutes and the car is not pulsating (revving high and low) anymore but you have to push the accelerator all the way down for the rpm's to go up and then they only go up a little. I am assuming this is "limp mode". Does anyone have any suggestions or ideas on what I need to do or what I may have done wrong? Thanks, Dave