High Idle Speed

[samboss]

Hi everyone, ive been racking my brain with this problem and i cant get anywhere. When i drive my 5L statesman (auto) for a while and it gets hot, the idle speed when i stop at the lights or something is really high, between 1200- 1500 rpm and the downshift starts to get noticable. i have replaced the TPS recently and cleaned the IAC just the other week. Has anyone got any ideas or heard of this before?

 

[304runner]

if you put it in P or N and give the throttle a really fast & quick tap, does it go back to normal?

 

[aceventura]

Are you having any starting problems? A bad alternator will connection can cause charging problems, and the ECU will increase the idle voltage to overcome this. It will also make the transmission downshift constantly to keep the revs up.

When the cable on the back of my alternator started to come loose, the car would show mild symptoms like this. One day the connection got so bad the idle went to 2000rpm and the car would downshift every time I took my foot off the accelerator.

 

[samboss]

304- ill try that next time, cheers.

ace- starts beautifully every time but i know the output of the alternator is quite low, around 12.9v, at idle. ive tried a new alternator and its the same. ill check out the connections as soon as it stops raining, cheers.

 

[BlackVXGTS]

Hi everyone, ive been racking my brain with this problem and i cant get anywhere. When i drive my 5L statesman (auto) for a while and it gets hot, the idle speed when i stop at the lights or something is really high, between 1200- 1500 rpm and the downshift starts to get noticable. i have replaced the TPS recently and cleaned the IAC just the other week. Has anyone got any ideas or heard of this before?

Did you start to have these problems before or after you replaced the TPS and cleaned the IAC? Make sure that your throttle cable isn't adjusted too tight. It needs to be quite loose otherwise you'll get the symptoms you describe.

 

[samboss]

a tight throttle cable would cause the car to idle high all the time- mines just when it gets hot. also i had the problem before i cleaned the IAC which is why i did it. thanks for the suggestion though