Please help...93 N/A high RPMs

[pwpanas]

Originally Posted by uberbg

ok i took it to the dealer again and got it checked again and they said that the problem would be an exhaust leak and they have to take the engine head out to fix it so they want 1600 for labor...
so i took it home and disasambled the idle control motor cleaned it and put it back on the car....i started it up it worked at 700rmps for 1 minute and then it went back up....
i tried to do it again but it wont go down like it did the first time.
so i'm not sure if that would be the problem or the trottle position sensor or something.
i'm gonna buy used idle contorl motor if i find one from sc300 or something hopefully it will fix it...

It's possible the problem is in your wiring harness. I'd suggest it's time to break out the multimeter and verify continuity and eliminate the possiblitity of shorts in the harness between the ecu and the idle air control (iac) motor.

I agree swapping the iac motor is another thing that you could try. I believe the TSRM has specific steps you can take to verify the correct (or faulty) operation of your IAC motor.

Disclaimer - it's VERY hard to troubleshoot problems like this over the internet, without having the car here in person. If you don't mind the exteme limitations of trying to troubleshoot like this, I'll stick with it for as long as you would like. Please keep in mind this type of troubleshooting could lead to some wasted expense and extra time for you. Using the TSRM would be one way that could be more efficient.

Note: The TSRM (Toyota Supra Repair Manual) has a comprehensive set of troubleshooting steps that covers almost every problem. It'll pay for itself several times over if you want to work on your own Supra.