I need help

4runnerChippy

New member
My 99 4runner had a leaky injector so i replaced the oring on it. since then i had high idle problems and lean bank 1 code, but it was running rich. I took everything back apart, had injectors serviced and cleaned, replaced intake manifold gasket and cleaned all in there, replaced upper and lower plenum gasket, replaced tb gasket, cleaned tb, and still when i start it, it high idles. after 5 min the idle drops but feels like its struggling a little. i attached the live read outs, any ideas.

thanks

The photo with 1400 idle is just after starting.
the photo with 680 idle is after about 5 minutes.
the other two are after warmed up as well

SORRY photos are sideways. don't know how to change now
 

Attachments

  • IMG_1368.jpg
    IMG_1368.jpg
    101 KB · Views: 466
  • 59477578067__4B5CA79B-D38E-45AB-AB2D-6CDFE1F42D17.JPG
    59477578067__4B5CA79B-D38E-45AB-AB2D-6CDFE1F42D17.JPG
    97.6 KB · Views: 432
  • 59477583313__E9BC638F-760F-4CA2-AC00-ADE1C317EF6A.JPG
    59477583313__E9BC638F-760F-4CA2-AC00-ADE1C317EF6A.JPG
    96.4 KB · Views: 509
  • IMG_1371.jpg
    IMG_1371.jpg
    73.8 KB · Views: 452
Register to hide this ad
You sure you dont have a vaccuum leak as our hoses are old and can split quickly. Rough idle can sometimes be from a vacuum leak.

Sent from my SM-J337V using Tapatalk
 
You did clean out your IAC valve also?
Were you careful with the cleaner when you cleaned your throttle body?
A hung up valve will create a lean condition and rough idle.
Your 1400 high idle seem normal. Mines goes 1500 then settles at 700 (pending weather).
 
You did clean out your IAC valve also?
Were you careful with the cleaner when you cleaned your throttle body?
A hung up valve will create a lean condition and rough idle.
Your 1400 high idle seem normal. Mines goes 1500 then settles at 700 (pending weather).

i believe i did yes. how would i know if i have a hung up valve, i did use seafoam
 
Iac

so today i took off IAC and tested with power and it would open, but never closed all the way, not sure if normal. I put all together and it still high idled. So i said screw it and unplugged IAC, and what do you know 700 rpm idle! plug it back in and 1400 idle. Drove it around and drove great minus the CEL for IAC. Came back let it sit and started up, idle is around 1100, but soon as i plug IAC in it tries to die. So i bought an original IAC off ebay and hope a new one fixes it
 
I think what your truck is doing at this point sounds normal. What is the temp outside where you live? My 3rd gen T4R also idles at about the same rpm on startup, then calms down and idles at about 700rpm after warming up. Did you disconnect the battery before starting it back up after doing all that work? Also, if you are in an area where there has been some crazy temp swings, that will affect it strangely sometimes too. Especially the higher the mileage.

Its also a bad idea to run the vehicle with the IAC out of the throttle body. They can overextend and then not want to retract correctly when re-installed. Its not surprising that removing the IAC caused the idle to come down.
 
Ah warmer climate. In PA here right now we are close to 40 degrees and falling. It's very common for ours to high idle this time of year as our lows the next 2 nights are in the 20 degrees. Keep us posted on your progress. :)

Sent from my SM-J337V using Tapatalk
 
i mean, IAC plugged in high idle, unplug normal. Has to be the IAC right? god i hope so, I'm so tired of trying stuff. Have'nt been able to smog or register it because of CEL.

BTW is the iac flap supposed to close all the way? i put power to it flap moves but doesnt close all the way.
 
i mean, IAC plugged in high idle, unplug normal. Has to be the IAC right? god i hope so, I'm so tired of trying stuff. Have'nt been able to smog or register it because of CEL.

BTW is the iac flap supposed to close all the way? i put power to it flap moves but doesnt close all the way.

If it closed all the way, there's be no airflow to the engine and it'd die, I would think.

Do you have the odd but possible issue where your butterfly valve in the throttle body itself is the culprit? Some people have reported wear on the valve itself so it's no longer flush with the housing, allowing air to get past and cause high idle issues. Usually becomes more pronounced after a throttle body cleaning since the gunk is no longer there to seal the gaps.
 
i mean, IAC plugged in high idle, unplug normal. Has to be the IAC right? god i hope so, I'm so tired of trying stuff. Have'nt been able to smog or register it because of CEL.

BTW is the iac flap supposed to close all the way? i put power to it flap moves but doesnt close all the way.

If you did this before the engine was at operating temp or within a couple minutes of restarting it when it was at/close to temp, then it's normal operation for the IAC. If your idle does not drop to 700 rpm +/- 50 rpm with the ac off once the engine is warmed up then you have an air problem. Not necessarily an IAC problem. 1500 rpm +/- 100 rpm is normal for warm up idle in park or neutral. This information is from a 2000 factory service manual.

What codes do you have?
 
If you did this before the engine was at operating temp or within a couple minutes of restarting it when it was at/close to temp, then it's normal operation for the IAC. If your idle does not drop to 700 rpm +/- 50 rpm with the ac off once the engine is warmed up then you have an air problem. Not necessarily an IAC problem. 1500 rpm +/- 100 rpm is normal for warm up idle in park or neutral. This information is from a 2000 factory service manual.

What codes do you have?

I had a lean bank 1 code after changing fuel injector o ring. Since I did everything that code hasn’t come back yet. The high idle is what’s lingering. I don’t remember it doing it before I replaced the oring the first time. As of now there are no codes
 
I had a lean bank 1 code after changing fuel injector o ring. Since I did everything that code hasn’t come back yet. The high idle is what’s lingering. I don’t remember it doing it before I replaced the oring the first time. As of now there are no codes

What's the idle before the engine warms up? Around 1400-1500 while in park with the ac off?
What's the idle after the engine warms up? Around 700 rpms while in park with the ac off?
 
I FIXED IT! i think. for now atleast.

So i put the new IAC on with no change still high idle. Angry and irritated i left it alone to start reading again. Thats when i remembered i bought a new MAF sensor month back. So i thought what could it hurt, even though i didn't think that it would work. Well what do you know! Idle is down to 950. I also found a vacuum leak from PCV to intake manifold, under that black foam piece, so ordered a new hose! Real test will be to see what it does when cold.
 

Members online

Forum statistics

Threads
278,304
Messages
3,554,041
Members
248,016
Latest member
Advally Service

Trending content

Back
Top