My DH thinks my truck idles too high when cold and doesn't idle down quick enough so is stressing the u-joints more than it needs to.
It starts at about 1200 and warm idle is around 700. I've never noticed how long it takes to idle down after a cold start, I'm always running late so get going right away. lol
I thought I had read somewhere here that Rangers tend to idle high but I gave up searching for the info after 6 pages.
Is it idling too high and how is it adjusted, if need be? Thanx

 

The idle speed is controlled by the Idle Air Control (IAC) solenoid & is computer controlled.

The computer uses inputs from other sensors, like the Engine Coolant Temp (ECT) sensor, Mass Air Flow (MAF) sensor, speed sensor, Transmission Range selecror (TRS), Throttle Position Sensor (TPS), Air Intake Temp (AIT) sensor, Oxygen (O2)sensors & some others I've probably forgotten, but anyway it uses a number of these inputs to decide how to have the IAC control the engines cold & warm idle speed & engine speed between shifts.

SO, if any of these sensors are sending the computer corrupt info, it can get confused about what to tell the IAC to do about the engines idle speed.

Or the IAC could have faulty electrical contacts, be dirty internally & hanging up, or just worn out & in need of replacement & it's a common problem part for idle speed troubles.

All that said, the overall idle rpm speed range you've posted isn't abnormal, unless the IAC is hanging up, say when coming to a stop, or between shifts the idle speed is so high as to cause rough shifting problems, or it's hanging up for long periods when the engine is cold.

Do you have a CEL lit, if so have the computer scanned for trouble codes & post all of the computer trouble code numbers stored.

 

I actually just replaced the IAC last week, I posted a thread about the truck nearly killing me with a stuck throttle or something and that was one quick fix suggested to do just in case.

It runs no different than before and I think my scare was just a fluke but it didn't hurt to replace it.

I personally don't think there is anything wrong with it. I have no other issues at stops or anything, she runs great and the idle has been this way since I bought it 3 years ago.

I had a CEL last year that had been on for ages, the scanner said it was on O2 sensor. It came on not too long after adding the CAI and we think it was just adjusting to that, the Durango did the same thing after the CAI was put in it. When it was time to get my inspection sticker he just unplugged the battery and it went out, it hasn't come back on since.

I just can't convince DH that the idle is normal for my truck. I don't know if it's because he isn't used to newer engines, he's old school and only owned older vehicles till he got the Durango 5 years ago, or just plain hard headed. lol

 

My 3.0 idles about 1200 when cold too. I'd say it's pretty normal.

 

I would say that high idle is, if anything a little low......About 1500/1600 rpm is what I have noticed with 4.0s high idle..........I dont think its anything to worry about.

 

Your idle #s are pretty much identical to my '91 Ranger 4.0. I believe it to be normal and whoever came up with the whole "stressing the u-joints too much" scenario must either be joking or on some good dope. I can assure you that the u-joints are under much more stress when it shifts at wot then shifting into gear at 1200rpm.

 

Well the CAI may be upsetting the air flow past the MAF sensor & if you've installed an oiled cotton gauze or foam type air filter in your new CAI system, they are known to foul the MAF sensor, so then it would send corrupt air flow info to the computer.

If your problems came about after installing the CAI system, then maybe suspect something about it is upsetting the MAF sensors PID output to the computer.

Did you ever replace the O2 sensors????