Anyone completely replace their throttle body / IAC ?

BrianSD_42

BrianSD_42

New member
I have been having low idle issues for a while now. I have thought about replacing the IAC with a new one $220 and cleaning the throttle body.

Only thing is that a lot of people seem to have high idle issues afterwards.

Has anyone just replaced the whole throttle body with a used one?
 
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If it's not throwing codes for the IAC sensor, then I don't see any reason to replace it. You can clean it with MAF cleaner and probably get away with it.
 
Ive cleaned it several times and the idle is still suffering IAC issues.

As far as low goes, it sits around 600 rpm and the engine is rough, but occasionally it idles at 700 rpm and is totally smooth.

I had it checked out by a toyota mechanic over a year ago and again recently. I was told that because the IAC is so old and probably corroded with junk i would be much better off swapping it out.

I found an entire throttle body on ebay for $120 w/ an IAC from a wrecked 4Runner with 93k miles. I currently have 213k miles.
 
At $120, it won't break the bank if it doesn't solve the problem. Based on past experiences and what you've shared in this thread, could it be that you have a vacuum issue somewhere? Like a loose or cracked hose?
 
Thanks for the comments guys,

I havent gone into a lot of detail but here are the symptoms:

At startup it occassionally will not start and idle correctly ... it will start but die within 10 seconds unless i put my foot to the gas and then drive around in 2nd for 10 mins or so.

Also it idles around rough @ 600 rpm not 700. The truck is supposed to idle at 900. As soon as i gas it to at least 700 it smooths out. No CEL, no other issues.

I have had these issues for over a year with no change. I have already cleaned the iac with a cloth and cleaner but it didnt help much. I also had a Toyota mechanic check it out.

My original idea was to take off throttle body and do a full cleaning but I have read that MANY members throttle idle was very high / messed up after cleaning due to warping of a 200k miles wear & tear.

I think i am going to just buy the ebay part. It comes with a 90 day money back warranty.
 
I was having the same issue as you, rough starts/dies, rough low idle, etc. Then a couple weeks ago exiting the freeway after about a 60 mi. commute it completely stalled out on the off ramp. Tried to restart and it would just die. I had to keep my foot on the gas to keep it idling. Drove it home with absolutely no other issues other than the fact it would not idle. Never got a CEL. Pulled the TB and tore into the IACV... it was filthy! It took an entire can of TB cleaner and an assortment of brushes/scrapers to get it cleaned up. Afterwords I used another can of cleaner and attacked the TB. Before bolting back together I tested the solenoid for functionality, then slapped everything back on reusing the old gaskets. Fired right up, and haven't had a rough start/idle issue since.

You said you already cleaned the IACV, but then said you were afraid to remove the TB due to warping. You have to remove the TB to get to the IACV. Did you remove the IACV to clean it, or are you just spraying down the hole in front of the butterfly?
 
brianemc2_42 said:
Thanks for the comments guys,

I havent gone into a lot of detail but here are the symptoms:

At startup it occassionally will not start and idle correctly ... it will start but die within 10 seconds unless i put my foot to the gas and then drive around in 2nd for 10 mins or so.

Also it idles around rough @ 600 rpm not 700. The truck is supposed to idle at 900. As soon as i gas it to at least 700 it smooths out. No CEL, no other issues.

I have had these issues for over a year with no change. I have already cleaned the iac with a cloth and cleaner but it didnt help much. I also had a Toyota mechanic check it out.

My original idea was to take off throttle body and do a full cleaning but I have read that MANY members throttle idle was very high / messed up after cleaning due to warping of a 200k miles wear & tear.

I think i am going to just buy the ebay part. It comes with a 90 day money back warranty.
Click to expand...

Sorry, my comment wasn't clear. It should have read *my experience*.

That new part will obviously tell you whether or not its tb/iacv related. If not, you'll likely be able to cross them off the list and move to something else. Good luck - iacv type problems can be frustrating.
 
brianemc2_42 said:
The truck is supposed to idle at 900. As soon as i gas it to at least 700 it smooths out.
Click to expand...

This is incorrect, Brian. Spec idle for the 3.4 is 700 +/- 50. For the 2.7 it is 650-750. I know it's the same thing, but I am copying exactly from my FSM and that's the way Toyota has them.

I agree with the post two above mine. How did you clean the IAC? I am not sure about the warping part, I only remember one case where someone had to change the throttle body. And taking it off did not cause the issue, it was removing the crud. I'd clean it right, first, and then invest in a new IAC before buying a used TB and a junker IAC. Have you tested the IAC?
 
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My 4Runner gets rough when the idle is at 600 or lower. Sometimes it even likes to idle at 550. But just like Brian, if it's at 700rpm or higher, it's very smooth.

I have plugs and wires and a bunch of maintenance that I still need to make time to do. I'll probably pull the whole intake off, clean the IAC and clean the TB too. The one IAC I have taken apart and cleaned on a friends truck was VERY dirty.
 
This is incorrect, Brian. Spec idle for the 3.4 is 700 +/- 50. For the 2.7 it is 650-750. I know it's the same thing, but I am copying exactly from my FSM and that's the way Toyota has them.
Click to expand...


Thanks!

Yes mine smooths out at 700 but i have to manually give it gas. It seems to be at 600 and rough unless i intervene.
 
You said you already cleaned the IACV, but then said you were afraid to remove the TB due to warping. You have to remove the TB to get to the IACV. Did you remove the IACV to clean it, or are you just spraying down the hole in front of the butterfly?
Click to expand...

What actually happened was the mechanic I usually go to cleaned IAC with a specially built tool (homemade) but he told me it might not have been that effective. He only charged me $20.
 
brianemc2_42 said:
What actually happened was the mechanic I usually go to cleaned IAC with a specially built tool (homemade) but he told me it might not have been that effective. He only charged me $20.
Click to expand...


Hm. Homemade IAC cleaner tool? They're called Q-Tips and carb cleaner. lol. But really, the only way to get it really clean is to take your time and just scrub it out really good with the aforementioned items.
 
brianemc2_42 said:
When i get the 93k TB in the mail i plan to clean it well. That is where i am leaning.
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Just a note, the screws securing the IACV to the TB are a real PITA to remove, and very easy to strip out if you're not careful. I used an impact driver and a well fitting bit and they loosened up easily. I also suggest new gaskets. I reused my old ones only because I was in a bind to get it back on the road. The metal TB to manifold one was fine, cleaned it up a bit with a little TB cleaner. The rubber IACV to TB one looked ok too, but didn't want to sit perfectly in it's groove. It was a b*tch to get back in. Haven't had any problems, but had it been a planned repair I would definitely have had new gaskets in hand before tearing into it.
 
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