I have an 01 ranger. It idles at about 1100 rpm. I cleaned the throttle body and I also cleaned the idle air control valve. Both did not fix the problem. Does anyone have any other suggestions on what I can do to fix the issue. Thanks for your time.

 

Is the CEL on? Any pending codes? Do this for us... While engine is running, unplug the IAC valve. RPMs should drop real low or even stall when you do this. Let us know the results. You can also test the IAC. See Attachment: Idle Air Control (iac) Valve.pdf

 

OP has a 3 liter, so unplugging the IAC valve isn't enough to check for vacuum leaks.
If it's unplugged idle may fall to around 750 or somewhere between 100 and the 500 rpm mark, but it won't fall to 500 or stall.

The IAC valve has to be physically removed and the holes in the throttle body blocked off, you will only then get a true vacuum leak test.

This has to be done this way because the IAC valves don't close tight shut when they're disconnected from a power source.
My new one doesn't nor did my old one.
I went to two auto parts stores and in both cases, the valve's seat was not right shut.
It's closed far enough that if it was disconnected, it would force the truck to idle below the computers target rate, but it doesn't shut right off.

You have to remove the valve and plug the holes in the throttle body to get a true vacuum leak test.

The photo shows one from Standard Motor Products, you can just see that the seat is not actually closed all the way.
You can push the seat shut with a small screw driver, but it won't stay there.

 

Grumpa, I unplugged the IAC and the rpms dropped to about 500 or 600 rpm. Jeff R 1, with all of the vacuum lines do you know which one would cause the high idle.

 

I forgot to mention that I have not had a CEL.

 

IAC valve unplugged and idle now at 500 to 600 rpm, probably don't have a vacuum leak.
So don't worry about that for now.

Pull the IAC valve and clean it with some carb cleaner. It's probably black on the inside.
If you can find a small brush small enough to get in there, then that's OK.
Don't use any type of brush with metal bristles.

You can get a CEL from disconnecting the valve, but after a few driving cycles, it will go out.

After going through more then 20 pages of doing a "high idle" search, a dirty IAC valve was the most common problem.

When you pull the valve, take note where the plunger is, is it in the same as the photo ?
What make is your IAC valve, probably Ford, but I would like to know ?
Thanks !

 

Jeff r 1. I had the IAC and the throttle body off the truck today and cleaned them both. I cleaned the IAC with q tips and a non wire brush. If I remember correctly That black seat was down. I tried to move it with a small screwdriver and it only moved a little. Are you thinking maybe replace?

thanks

 

Wait till the engine is cold (over night).
Unbolt the throttle body and it should be closed (as far as it will go)
Have someone turn the key to the "on" position, it should move open for cold engine high idle.

If it doesn't do these things, then replace it.

 

And I just checked over at RockAuto, they're all about the same price, so get the MotorCraft one.

 

Hey thanks Jeff r1 for the help.

 

One more thing, what is the normal idle rpm for my truck. I just bought it so I’m m not sure

 

Can't remember for sure _ depends on Auto or Standard.
700 to 750 for Standard, maybe a bit higher for an Auto, but certainly not 1100.

How does the truck run otherwise ?
Has it always idled at 1100 or has it started to do this ?

Someone may have been messing with your anti-dieseling screw thinking that it was an idle adjustment.

 

Ive had the truck for just about 3 weeks. It’s always idled at about 1100. Other than that it runs pretty good. The transmission down shifts a little hard when stopping but I think that is due to the high idle.

 

You need to check you TPS (throttle position sensor) voltage at fully closed position.
Watch this video, let me know if you have any questions.
Fully closed the TPS voltage should be at .7 to .99 volts, not over 1 volt.

However if it's set at more then one volt, you should get a CEL.
When putting needle probes into the connector, make sure they don't touch.

 

EDIT
Forget if the anti-dieseling screw was turned out too much, the idle wouldn't fall to 500 or 600 rpm.
I'm thinking too much.

 

Great video. I will try to do this tomorrow after work. I’m tempted to mess with the adjustment screw but I don’t want to add to the problem. I did read somewhere that after cleaning the IAC and the throttle body that I should have reset the computer by disconnecting the negative cable. Have not done that. Thanks for all of your help. Ill let you know how it goes.

 

Thanks JeffR1, That's info I can use in the future. My truck idles at around 930rpms at operating temp and @830 at idle in gear. Hows that sound?

 

Don't touch the adjusting screw, the fact that the RPM drops to 500/600 rpm indicates that the screw is set right when the IAC valve is disconnected.
It won't hurt to follow the procedure in the video to check that your TPS is OK though.
I'll think you'll find you won't need to touch the screw at all _ being that it's in spec below .9 to ,7 volts.

Here's a post from Ron to answer that question.
He's talking about a 4 liter, but it should be the same.
Does your idle fall when the IAC valve is disconnected and if so what is it ?

https://www.ranger-forums.com/genera...0/#post2120763

 

 

Jeff r 1, just wanted to give you some feedback. I didn’t have time to take the IAC off but I did unplug my negative battery cable for about 30 minutes and now it idles at about 800 or 900 rpm. Not sure if that is normal but it’s better. By silverado idles at about 500 or 600 rpm. The one thing I noticed is If I rev the engine it will stay at about 1500 rpm for a few seconds before it goes down to 800 or 900. Thanks again for all the help.

 

Assuming the Silverado has a V8.
V8's generally idle slower the a V6.

 

I know with mine it took about a week of driving before my idle settled down, so it would seem that it takes the computer a long time to learn its target idle after unplugging the IAC valve.

 

Thanks again to all!

 

Just for the heck of it I threw my code reader on the truck and even though I didn’t have a CEL on I had 2 codes. One was the IAC that was the result of unplugging it yesterday and the other was an ABS code. I don’t have ABS light so I’m curious what it could be. I read that it could be a fuse. Anyways I really appreciate all the help and info, I learned quite a bit from this.