I have read all the posts on HIGH IDLE problems and thank you all for the good info it has helped me fig out a lot . So know I have a 99 ranger 4x4 5spd no cel , Heres what I have came up with so far have sprayed ever thing with crab cleaner to check for vacumn leaks , cleaned throlle body,, new IAC, MAS , NO fix high idle check voltage on tps set at .90 like other post no change after hooking batt back up and going through the pcm relearn , So here what I did out off desperation , turned throllte body idle screw out , by the way lowest voltage was .83 screw in my hand , did pcm reseat un hook batt 15 mins , Started it up and it would IDLE at about 850 much better ah but wait went through the 5min idle no functions fan lights AC , then 5 min AC , picked a little while it was running ac DANG i was happy , did them 4 times each but never did my foot thouch the throttle , Well fig it was fixed went to test drive and rpms picked back up to about 1350 and will not return back to 850 unless i shut it off and restart stays at 850 good until it thouch that dam fuel pedal oh ya by the way cable not stickin has a little sage in it even OK so can this be fixed Please ,,,,Sorry for long post just wanting to let you know that I am reading what you guys have told us high idle suffers to do ,,,

 

Drive at least 100 miles , without pulling the battery cable , and get the codes read.
Not all codes will throw a CEL.
Open the throttle plate by hand all the way and inspect the throttle bore for any little groove where the butterfly may have worn into it. Also try to move the butterfly shaft up/down/sideways to check for any play.

 

I prefer basil myself.

 

There is a small groove on the bottom noticed it when I took it off to clean the throttle body two weeks ago, The shaft ,, end play,,, is snug , So now I need a new throttle body because of the groove , That is the reason it hangs at a high IDLE after touching the gas pedal , but then shut motor off and it returns to normal idle until the touch the fuel pedal again , Thank you for the help ,,,,,4door

 

Well I took your advice About driving it a 100 miles [ not quite 100 miles ] and when we left the house we had a 99 ranger 2 door excab 4x4,,3.0 5spd ,,When we got back home it became a 2001 excab [ 4door ] 4.0,,, 5spd ,,,4x4,,, , it runs very good ,,thank you for your help NOW A ,,,,4 door

 

My sons 2000 has had the high idle on and off for awhile. Replaced TPS, IAC, and DFPE. With each replaced part it got better then came back. Cant find a vacuum leak. Throttle body is not worn so I went ahead and cleaned it with a towel and carb cleaner. He says it runs alot better. Maybe you have to clean the throttle body now and then.
If it comes back I was thinking about temporarily blocking off the IAC holes to the intake with some thick gasket material and installing the IAC over it. I wonder if it is letting air in when it is not supposed to.

 

In case you don't know , IAC stands for Idle Air Control. It is a stepper motor , contolled by the PCM that allows air to bypass the throttle plate and is what regulates idle speed. Blocking it off will cause the engine to not idle at all ,UNLESS there is a vacuum leak.

 

Its been a few weeks and the high idle has not returned. The new DFPE from ebay was causing a CEL for insufficient EGR flow. Put the old DFPE back in (probably the original) and CEL has not returned. Contacted the DFPE vendor and they said it was the electrical connector and to take it to the Ford Dealer for a connector replacement. Some of these online parts dealers really suck but I dont have the energy to fight with them to get my 40 bucks back. Suggest getting an OEM DFPE if you are replacing it. I think cleaning the throttle body with a towel and carb cleaner fixed it. Read somewhere that you are not supposed to use a towel because it will remove the coating but just spraying it didnt remove all the carbon.