Extreme High Idle

[JayT]

So I start up my '03 Ranger with 2.3L engine today, and idle was a bit high, but it is cold, and it dropped down pretty quick. However by the time I got to the end of the driveway and put the clutch in the idle ran up to around 3200 RPM and was slightly revving up and down a couple hundred RPM. It continued to act that way as I drove so I came back. If I leave it revving at 3200 for about 10 seconds it drops back down to a smoother but still high RPM of around 2200.

I have read some of the high idle threads on here, and am going out to mess around with the IAC and TPS, and look for a vac leak, but will appreciate any help I can get in solving this if I am on the wrong track.

 

[JayT]

Ok, my experiments did not last long because it is cold and windy. I'm thinking to rule out a vac leak because of the idle fluctuating the way it did. I tried 2 things. I disconnected the wires to the IAC. There was no change. Then I hooked the IAC back up and disconnected the wires to the TPS, and after a few seconds the idle shot all the way up to 4500 RPM.

 

[JayT]

I changed the TPS because it was easy and only $20, but there was no change. My philosophy on that is it is not just throwing parts on it. With 140k miles and 10 years old, most any original part is due for replacement. Then I took off the IAC and found debris stuck in the valve holding it open. I got that out and cleaned the IAC with brake cleaner. It will be dry soon, and time to reinstall it, and I will update accordingly.

 

[JayT]

That was it! Idle back to normal. All driveablity back to normal. I hope this helps somebody who has a similar problem. My advice is to check and clean the IAC first. I did it backwards.