New High Idle when Warm Problem (1 Viewer)

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650 is normal, so that's fine. Oil pressure gauge is low. On mine that's an indication I need to top it off. Could be a bad oil pressure sensor as well.

I'm not sure that his gauge is off all that much. Mine is similar at idle especially when I am closer to needing an oil change. If you are truly concerned that your oil pressure is an issue that hook a mechanical gauge up and see what kind of numbers you get. If I remember correctly at idle the oil pressure is somewhere in the neighborhood of 7psi and at 2-3000 rpm's it's around 70psi. A search would get you more precise numbers and perhaps it is in the FSM, but I cannot recall for sure.
 
A follow up from earlier today. On my way home I experienced the same high idle conditions as previously described, although it didn't seem as high before I swapped the IAC valve. Early this evening I tore into the throttle body to give it a once over. I thoroughly cleaned it (and it was very dirty) and while I was in there I change the spark plugs and cleaned up the MAF sensor.

Once everything was back together I took it for a test drive and while the ambient temps weren't as high as when I drove home, it was still rather warm. I got the truck up to operating temps and the idle was fairly normal. We'll see what tomorrow brings when I am able to get some day time temp driving in.

When I got back to my garage I was going over the FSM, I came upon page EG-155, which covers a component called the Throttle opener. According to the FSM it appears this component operates in a RPM range of 700-1000 RPM's. If the throttle opener has begun to fail, I wonder if this may be the cause of the elevated RPM's?

Thoughts?

So a follow up to Friday evenings maintenance. I didn't drive her at all this past weekend, but I did today. With ambient temps back in the 80's I was hoping to get close to the driving conditions we had last week. By the time I got to work the truck was up to running temps and it was warm enough I figured I would be able to repeat the high idle symptoms as described previously. Well, nothing. She idled exactly as intended. It was even warmer (mid 80's) out on my drive home and never had any symptoms.

Conclusion, well I am not exactly positive, but the thorough cleaning of the throttle body seemed to do the trick. Time will tell and I'll follow up.
 
So it's been a month now since I performed the throttle body cleaning and am happy to report, no high idle when warm.

We had temps in the low 90's yesterday and in the mid-80's prior to that and the engine performed as it was intended to.
 
Well it's been a little over two years and just today on my way from work these symptoms returned. I'll be cleaning the throttle body again to hopefully eliminate the issue.

Perhaps two years of primarily driving in the city has caused an increase in carbon deposits.
 
Well it's been a little over two years and just today on my way from work these symptoms returned. I'll be cleaning the throttle body again to hopefully eliminate the issue.

Perhaps two years of primarily driving in the city has caused an increase in carbon deposits.


Did this resolve your issues again?

I am experiencing similar issues for the first time and I am wondering if I should address the throttle body.

I had an O2 sensor code a while back and I cleared it and it has not come back. I'm not sure if mine is an O2 sensor issue, a connector issue, or dirty TB.

I would appreciate your feedback.
 
Always start by making sure the throttle plate is really really really closing. Way too many cases where folks are "pretty sure it is" and then go off in different directions for months or even years at a time.

Get under the hood and check all the cables, the dashpot, see if you can cause and/or temporarily cure the issue by manually operating the throttle, etc.
 
Always start by making sure the throttle plate is really really really closing. Way too many cases where folks are "pretty sure it is" and then go off in different directions for months or even years at a time.

Get under the hood and check all the cables, the dashpot, see if you can cause and/or temporarily cure the issue by manually operating the throttle, etc.


Roger that. I will check it out. Thanks!
 
Did this resolve your issues again?

I am experiencing similar issues for the first time and I am wondering if I should address the throttle body.

I had an O2 sensor code a while back and I cleared it and it has not come back. I'm not sure if mine is an O2 sensor issue, a connector issue, or dirty TB.

I would appreciate your feedback.

I inspected the throttle body and it is dirty again. But so far have ended up dealing with it as I only experience the symptoms when the ambient temperature is over 75-80*F. Perhaps, I'll get around to cleaning it this spring. At which time I will follow up.
 
I inspected the throttle body and it is dirty again. But so far have ended up dealing with it as I only experience the symptoms when the ambient temperature is over 75-80*F. Perhaps, I'll get around to cleaning it this spring. At which time I will follow up.

Thank you! I appreciate the response. I was experiencing the issues while driving in a high humidity conditions with ambient temps being about 56°F. It had been extremely cold here, then a quick drastic warming trend and there was moisture on everything without it raining. I had not experienced anything other than the O2 code to date. I'm leaning to the O2 sensors and their connections, but I will check the cable and the I may peek into the TB.

Thanks again!
 
Always start by making sure the throttle plate is really really really closing. Way too many cases where folks are "pretty sure it is" and then go off in different directions for months or even years at a time.

I'm leaning to the O2 sensors and their connections

See? :lol:

Not even worth leaning towards anything till you thoroughly check all the mechanical sh*t. And don't forget: High idle needs more air, period.

So what exactly are your symptoms anyway? How high of an idle? When the engine is cold? When it's warm? Is it a consistent problem now, or just sporadic?
 
See? :lol:

Not even worth leaning towards anything till you thoroughly check all the mechanical sh*t. And don't forget: High idle needs more air, period.

So what exactly are your symptoms anyway? How high of an idle? When the engine is cold? When it's warm? Is it a consistent problem now, or just sporadic?

It is sporadic. I cannot seem to duplicate conditions, but it appears to occur when the engine is warm. It is holding about 1800 RPM at idle. It makes it hard to hold in the drive-thru lanes....... This has only occurred twice when I've been driving it. I'm a bit of a stickler on maintenance because I like to have all my vehicles set up to jump in and drive 2500 miles at a moment's notice.

I'm going to check the mechanical as well (as I stated) because the cable/housing on mine has no rubber covering remaining on it and it MAY be getting stuck. This is my DD, so it "suddenly" sticking seems odd to me because it should be pretty shiny due to regular use.

I am just fishing at the moment for solutions and I am looking at prioritizing the possibilities. The mechanical check is free, so I'll do that soon, but it has to be high-idle for me to test the theory.......

I'll keep it updated.
 
No way that is anything other than mechanical. Period.

Just think how much air that requires, and how far you'd have to depress the skinny pedal to hold the rpm's there under normal conditions.

I have stomped the pedal to the floor multiple times and it comes back to the exact same place. Then, later, it drops down and is normal.

I have not been watching my O2 levels or anything on my UG during this time. Was distracted by my wife yakking at me.......
 
I have stomped the pedal to the floor multiple times and it comes back to the exact same place. Then, later, it drops down and is normal.

What I mean is: When it's *not* happening (idle is normal), think how far you'd have to depress the pedal to hold rpm's at 1800. Not anywhere near the floor of course, but still a significant amount. So, when you're experiencing the issue, that's how far the throttle plate has to be sticking open. O2 sensors (or whatever) simply can't produce an idle that high just by changing EFI parameters; the motor needs too much air to do that, period. And the only way air gets in (except a bit from the IAC valve) is past the throttle plate, which is mechanical. No ECU input or anything like that; just the skinny pedal.

Next time it happens, you should immediately pull over, put it in park, pop the hood, and get in there and play with the throttle lever. Pretty much guaranteed you'll be able to bring it back to normal by hand.
 
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What I mean is: When it's *not* happening (idle is normal), think how far you'd have to depress the pedal to hold rpm's at 1800. Not anywhere near the floor of course, but still a significant amount. So, when you're experiencing the issue, that's how far the throttle plate has to be sticking open. O2 sensors (or whatever) simply can't produce an idle that high just by changing EFI parameters; the motor needs too much air to do that, period. And the only way air gets in (except a bit from the IAC valve) is past the throttle plate, which is mechanical. No ECU input or anything like that; just the skinny pedal.

Next time it happens, you should immediately pull over, put it in park, pop the hood, and get in there and play with the throttle lever. Pretty much guaranteed you'll be able to bring it back to normal by hand.


Actually, my other thought was the IAC valve.

Thanks a LOT for your input!
 
Can you elaborate on that?

The rubber sheath on the outside of the cable housing (sheath) has all but disappeared. It appears to have been coated with plastic at some point in its life, but only a couple spots have any remnant of coating on the housing (sheath). It looks like a long rusty looking cable housing instead of a black plastic coated cable housing. The pic below is from 4 years ago. It doesn't have as much black plastic on it now as it did then.
IMG_20140816_111944575_HDR.jpg
 
Lol.

How can you possibly think that's not your issue? :lol:


Well......... You're right.

It finally repeated the condition today, so I tried your suggestion of popping the hood and pulling the throttle butterfly back and it dropped. I accelerated it, and it stuck high, so I made it repeat three or four times.

New cable on order today.

Thanks @CJF!

God I love this place!
 

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