91 explorer high idle

[craig661]

After driving my explorer for any amount of time, if i put in neutral the rpm's rev pretty high, any suggestions on how to stop it

 

[mawrazen]

Clean MAF and check for vacuum leaks. Also there is an idle speed adjustment screw on the throttle body intakes butterfly valve.

Also make sure the throttle cable and cruise control cable are not getting hung up. (Check springs)

 

[craig661]

thanks

thank you, i will look into those,

 

[Blacksheep Josh]

What is "pretty high"?

If I put mine into neutral, it's normally goes up a couple hundred rpms to around 1000. My Dad's did the same thing, I wouldn't worry about it, as you're not in neutral a whole lot.

 

[shaggymane]

Check the spool valve portion of the IAC. MAke sure it's clean of carbon and moves freely.

I've got the same problem going on. Thought I checked mine and found it dead. So I bought another one. 60+ dollars later still have problem.



I should have checked the Engine Coolant Temp sensor also. As I understand it, if the ECT isn't reading right, it'll tell the computer the engine hasn't warmed up yet and so runs on a rich setting or opens the IAC.

I don't know if the Intake Air Tempature sensor affects idle or not.



TESTING IAC

See Figure 2

1. Turn the ignition switch to the OFF position.
2. Disengage the wiring harness connector from the IAC valve .
3. Using an ohmmeter, measure the resistance between the terminals of the valve.

Due to the diode in the solenoid, place the ohmmeter positive lead on the VPWR terminal and the negative lead on the ISC terminal.

4. If the resistance is not 7-13 ohms, replace the IAC valve.

Go to autozone.com look in repair guides for the diaghrams of the IAC terminals and the chart for the ECT correct readings.

Good luck