High idle in P & N after driving (1600-2000 RPM's). Anybody have similar issue?

[S.CarolinaFZJ80]

Well my cruiser is now idling at 1600 -2000 RPM's after driving it and putting it into park. In all other gears, idle drops back down to 600-800 RPM range.

At first I thought it was due to high outside air temps of 95 F and hot intake air temp of 140 to 155 F & high water temp in the 190 to 205 F range. I thought that the ECU was having it idle higher to recruit more airflow from the fan. However, on a cool, wet 70 degree F morning it is still doing the same thing!?

Has anyone had a similar occurance & would care to share their thoughts?

I did all of the following repairs at once with no driving in between. Any connections between these and the high idle in P and N after driving it?
- Replaced starter & alternator with reman's from CDan (due to starter contact being stuck and toasting starter. Alternator was putting out 17 volts so regulator was shot, probabally due to starter issue.)
- Added 1 qt. of Gunk engine build-up remover to oil (Castrol High Milage 5W-30, ran for 5 minutes then drained overnight and flushed with 2 fresh qts. of oil and drained for 5 hours, replaced with Castrol Syntec 10W-30 (as per owners manual for temps above freezing through 100+ degrees F) & a Toyota 90915-YZZD3 oil filter. (removed the same model # oil filter)
- Replaced oil pump seal & crank case seal
- New Toyota A/C & Alternator belts
- Drained and refilled transfer case with Mobil 1 75W-90 (6,000 mile change interval)
- Drained, flushed and refilled diffs with 80W-90
- Added 1/2 tube of grease to steering knuckles (bringing them to 3/4 full)

Also, replaced Throttle Position Sensor 3,000 miles ago with a new Toyota one.

 

[Daisy 53]

Hey buddy have you run through a few start cycles with it yet? Everytime I disconnect the battery in mine it take 6 or 7 starts to let the ECU relearn all the settings it needs to adjust the idle.
If you have done that, im at a loss to help further.
Good luck
Daisy

 

[S.CarolinaFZJ80]

I have probablly have started it a dozen times on short trips of 2 miles to longer ones of 12 miles. I'm hoping I didn't get a transient electrical spike during my starter issue to the ECU that may have caused some damage!

BTW - Daisy53. I've been out to ABQ a few times and was meaning to look you up. I unfortunately had little time and had to visit CDan to pick up parts. I should be out there later this month if you are up for some wheeling?

 

[jlg32281]

Check your intake tube for cracks. Sounds like un-metered air is getting in.

 

[Daisy 53]

Heck yeah im up for some wheeling, shoot me a pm and i'll rally the troops!
As far as your issue goes, jlg has a good idea on what to look for. If that doesnt work, maybe the ECU is bad...
The only other thing I can think of might be the Idle Air Valve, the one right next to the TPS on the intake. Ohm it out and see what that tells you. There are a few posts on here that talk about putting an additional O-ring on it fix high idle at start.
Daisy

 

[S.CarolinaFZJ80]

jlg322281 - I will check it today.

Daisy53 - I will check this Idle Air Valve too and I will definetly PM you before I head out you way again. BTW - what Ohm range should I be looking for on that valve? In the meantime I will search the threads for putting an additional o-ring on it.

 

[Daisy 53]

The specs are in the FSM, not sure what they are off the top of my head.
Ill check back tonight and if nobody has given the specs, ill post them up.
Daisy

 

[CJF]

Make sure it's not as simple as a sticking throttle cable...

 

[CJF]

Check your intake tube for cracks. Sounds like un-metered air is getting in.

I've never heard of that *raising* the idle, only *lowering* it.

 

[cruiserdan]

Have you removed the throttle body?

Have you done anything to the accelerator cable?

It is possible that the cable is hanging up.

 

[S.CarolinaFZJ80]

The cable isn't sticking.

I checked the intake tube... No cracks and secure with the clamps on both ends.

When in P & N the idle is at 1600 RPM's initially then down to 1450 RPM's with the AC off and 1800 RPM's then down to 1600 with the AC on. When I shift to R, D, 2 or L it goes down to 950 RPM's.

It only happens after the vehicle has been driven. If I do a cold or warm start it immediately goes to 1200-1400 RPM's for a minute or two then slowly drops down to 800 RPM's.

When the wheel is turned i.e. the power steering pump working, it drops 50 to 100 RPM's. My Scangauge II was giving me a water temp of 190 degree F & intake air temp of 146 degrees F. Also, the IGN gauge function on it showed a value of 16 in P, 17 in N & 20 in R, D, 2, L.

I did notice a 3 way vacum fitting on top of what looks like the fuel rail, under the throttle body that has the most forward fitting empty. I searched around and can not find any loose vacuum hoses or any other empty fittings to match it too! See picture below.


Could this be the culprit?

 

[notthejeepnomo]

Mine was doing the same thing. it would idle from 1200-2500 in p and n. When it would do this i would pull the gas pedal back with my toe and the idle would come back down to normal. When i looked to see if the cables were sticking they were not. What i noticed is that on the throttle body there is an arm with a scew w/imbeded hex head and an 8mm nut. The arm is on the side of the throttle body nearest to the front of the vehicle, if memory serves. when the throttle body returns to the position correlating to idle the screw makes contact with a plunger(12mm cylinder). I simply adjusted the screw/nut so it comes into contact with plunger 1-2mm sooner. To adjust the srew/nut you can (while the car is off) turn the throttle body to the position correlating to wide open throttle and adjust it with an 8mm wrench and small hex. I don't have pictures. nor can i get them within the next 4 days sorry i work 13h nights and sleep all day.
peyton
Ps i don't have an fsm, but if someone would tell me what the plunger is, that would be cool.

 

[S.CarolinaFZJ80]

Every time that I try to reply to this posting with the two attached pictures mentioned in my previous posting I get the following message:




The following errors occurred with your submission:
The message you have entered is too short. Please lengthen your message to at least 5 characters.




What's going on with this? I've never had a problem posting pics before this.

 

[cruiserdan]

You need to have at least some text in order for the software to accept a post.

If you are trying to create a post with attachments only that is your problem.

 

[S.CarolinaFZJ80]

I have had text in all my attempts. The only thing that is working is the Quick Reply. the Post Reply with picture attachment is not working. I resized the pictures to very small with no luck.

Hmm, now I have two problems.

 

[S.CarolinaFZJ80]

nothejeepnomo - I will check that but it's not likely as everything up there was tight when I replaced the throttle position sensor not too long ago. Pedal is not sticking. Lifted up on it. I believe it is electrical every time i put it in P or N it happens.

by the way, good handle. I am a Jeep convert too. Well Jeep to Toyo (4 times) to Jeep to LC

 

[S.CarolinaFZJ80]

Cruiser Dan - Thanks for you help. I believe it has something to do with"running scripts" my computer prompted me something about it. It asked if I wanted the website I was visiting (IH8MUD) to coninue running scripts. I believe I clicked no but don't recall as I anted the annoying pop up to go away.

 

[S.CarolinaFZJ80]

Pics

Here is the picture.

 

[S.CarolinaFZJ80]

Another view.

 

[cruiserdan]

That there is a vacuum leak.