DIY: Replacing IACV
 

Hello Folks!


Well because bad things happen in a strike my IACV decided it was enough! After 210,000 Miles it crapped on my almost 4 days ago (Erratic Idling, Idle too high while in Drive). So I ordered a new IACV and decided to replace it and took some pics for reference.

The part I bought is the Standard/Intermotor "AC229" not to be confused with the cheapest AC229T the "T" is for the economy version from Standard Autoparts. AC229 is the one you want for the best performance and longevity its co-made with Intermotor which is a very good brand from UK that makes Motors & Coils.

Standard/Intermotor AC229 = Cost: 79.99 + Shipping = 86 bucks
Vs OEM = DENSO "1368091011" +200-320 bucks @ Dealership (hahaha they must be high)...

Parts needed to replace:
9mm Socket (For Air Box Not needed if you have CAI/SRI)
10mm Socket
12mm Socket
Ratch
Cleaning Rag for Coolant Leaks
Philips Screwdriver
1x Throttle Body Gasket if you don't have Aftermarket Spacers.


Well this is how the AC229 comes in:
Attachment 71839
Made in the good´ol US of A compared to DENSO which is not made in Japan but in México! "Not dissin´ just sayin´"...

Attachment 71840

Attachment 71841




Procedure:


1.- You need to remove your air box cover you will need either a Philips screwdriver (If your screws aren't rusted) or a 9mm socket if they are rusted and you already stripped the Philips head. Once out remove your intake tube by loosing the metal brace with a 10mm socket and unplugging the 2 vacuum assisted tubes. If you have a CAI or SRI just remove it.

2.- (Type-S only skip to #3 for TL-p) you need to remove your VSA Throttle Body which is held by a metal arm from the transmission with a single 12mm socket.. Loose the metal brace with a 10mm socket and remove the 2 Coolant Passages (They will leak coolant have a rag ready).
Attachment 71842


Attachment 71843

A trick to remove the VSA Assembly easily is by unplugging the VSA Sensor on the side and rotate the whole assembly a couple of degrees counter clock wise missing the metal arm so you can pull it out.

Attachment 71844


3.- You need to unplug 3 cables: MAP Sensor on the Top, TPS Sensor on the side and IACV from the bottom.
Once you have done that unplug the Vacuum tube from the side by pulling it out (It should come out without pliers) and remove the 2 coolant lines in the IACV then remove the 4x 12mm bolts and nuts holding the Throttle Body into the Intake Manifold it should now come off, Don't remove your Pedal/Cruise Lines you can flip the TB 180° to remove the IACV.
Attachment 71845


Now flip the TB 180° and you should clearly see your IACV being held into the TB by 2x Philips Screwdrivers.. If they are like mine they should un-screw easily.. If they don't you can use a Vise Grip to remove them as they stick their heads enough to have a grip on them.

Attachment 71846


4.- Remove the old gasket and replace with the new IACV gasket included in the box. Install the new IACV carefully making sure the gasket lines up.


5.- Basically Reverse Procedure, Burp your Radiator and your DONE! :thumbsup:


Old vs New:
Attachment 71847
Attachment 71848
Attachment 71849




Hope this Helps anyone as a Reference or as a DIY!

Holy Shieeett! Seems that my IACV wasn't acting just 4 days ago..
Idle is crazy smooth now and when the A/C kicks in it doesn't vibrate while in a stop like before (I thought my Poly mounts were shot!). Also when you kick down a gear in SS the car doesn't engine brake at all! it keeps the idle steady so the car keeps its speed.


Its crazy smoothhhhh!!! Best 86 spent evah!

excellent write-up

Did you remove the rod from old unit- to see how it comes apart for maintenance cleaning- when its off with EGR system cleaning job?
Help the others out!! you have one to play with~

I did took it apart but I had to be creative with the Star Shaped screws.. The rod itself doesn't want to come off, seems that the bearings are pretty much welded to the casing and I ended up destroying the magnet trying to remove the rod. I'll try to remove it with a heat gun later on but I found out that one bearing is shot.. Too much resistance while trying to turn it and it gets stuck, seems that the electric side was fine and the only thing to blame was the bearing :(

bearing failure of the iacv, who woulda thunk!

Interesting find on the part. I woulda guessed japan on the denso, and mexico, china, or ? on the intermotor. We've used some intermotor ignition stuff here at the shop with no problem: I'll have to start looking at the country of origin. Nice to be able to buy something made in the U.S.

^ That's what I found more disturbing.. dealer is asking an outrageous amount of money for a part that is being made (still made) south of the border. Ironically a part made in the US cost a fraction of that... Brand recognition much? I would at least think it was worth the price tag if it was made in japan, but I would still not pay that much for it.. Its a goddamn solenoid and a magnet for crying out loud!!! not a space rocket... even my starter was cheaper.

just bought mine hopefully i can do it when it arrives cause i hate WA weather so much

^ If you have any question don't hesitate to ask!

yeah im doing mine today after i drop my sis off at her appointment.....may be a noob question but how do i put that black spacer looking thing on the IACV? does it stick or do i need to glue it on? :3

When you have the TB flipped 180° just leave it there and install the IACV carefully.. I didn't have any problem with the gasket.

i couldnt even flip it there was two hoses that i couldnt take off because they had these special medal braces around them and i gave up but man putthing that throttle body take forever and now my damn medal screw is now sideways and loose and its not all the way on the throttle body the black part

You mean the A/F coolant hoses that goes into the IAC & TB? You need nose pliers to take those off. I don't understand very well your problem? Care to explain a little further? a picture would be great!

the two hoses on the bottom so yes i think....and umm i used the nose pliers and pushed it back but i cant pull the hoses off because theirs a thin tight metal holding the hose on and ill take a pic next time i take it off because i had to put it back together it was getting dark

https://cimg3.ibsrv.net/gimg/acurazi...de1daae2e4.jpg


That's the metal thing holding it and I can't pull it off

Use a prybar to separate the two pieces apart from each other then you should be able to slide the metal clip the rest of the way off.

Why your hose is straight? See my pic where the TB Coolant passage is? its pointing downwards! I'm seeing the diagrams and both TL-p and TL-S Throttle body coolant passage points downward, Both inlet (TB) and outlet (IAC).
Its yours a 1999? Because that's the only one I see with a Straight outlet.


In any case you seem to actually jumped the fitting in the outlet so you need to pull off. In any case if you cant remove, Remove the side that goes into the Engine.

On an Update from the AC229 this IACV does something that the DENSO didn't, Every time I start the car the RPMs would shoot to 1100RPM then settle down to normal idle after 2 seconds, Regardless of being hot/cold. In comparison the DENSO unit would always start the car at 900-800rpm, Basically start to idle.

Aside from that the car runs like a charm again! Shift kickdowns works wonders! the RPMs hold steady while downshifting in SS something the DENSO unit didn't do = There is less engine braking, I'm loving it

yes mines 1999 lol and both hoses i cant take off has that supid metal thing^ on it which is why i couldnt spin the TB 180 degrees but ill try again this saturday

Thanks for the great write up. Just did this myself on my 2000 TL. I am currently resetting my ECU. Is it normal for the the check light to stay on even after the part has been replaced?

Definitely got rid of my crazy bouncy idle.

Thanks!


Is not normal :(
If the IACV was in fact the issue the OBDII would clear itself almost immediately after the first start up.


Need to check that code and see if its something new?..

That's what I thought too, but ready to hear something funny? Pulling the fuse did the trick.... I was actually out of town for a wedding, so this DIY really saved me HUGE. It's been about 300 miles and no light yet. We'll see what happens. I was in such a rush I never even got the code read (which probably wasn't smart). I just saw the bouncing idle and went for the replacement.

Here's what it looked like:

https://i.imgur.com/jzbQZTa.jpg


https://cimg5.ibsrv.net/gimg/acurazi...a90c7a8ef2.png

Congrats bud! I just want to know if your Valve does the same thing as mine? can you check it? Once the car is HOT check if the car starts at around 1100RPM then settle back down. OEM IAC Behavior was to start at 800RPM when the car is hot.

Also try to hold a gear through SS and see if you notice less engine brake.

Mine definitely idles different, and I think it's similar to what you're describing. I've made a video. This was after the car only sat for about 40 minutes and it was in the sun and 85.

http://youtube.com/3L6RrBMMJ2g

As far as SS the only time I use that is when I'm on the highway with cruise on to prevent gear hunting on hills. So far I haven't noticed a difference yet, but I almost never use it in acceleration.

YES! Exactly the same! Its weird but well it works and its cheap...
Your link wasn't correct so I'm putting it here:

Yeah, sorry I was posting it from mobile, and it wouldn't post right. I've noticed mine sometimes now will idle at 800? I am not too worried about it. Until the check light comes back I am assuming all is good.

P.S. Happy belated birthday. I also turned 26 on 4/10. hahaha.

Thanks Man! and Congrats too!


The OEM Idle is between 700-790rpm so perhaps its near the top range? but nothing to worry about from the video.. Mine idles exactly the same as the DENSO so perhaps is the manufacturer range setting being a tad off.
With a PRO OBDII Scanner you can know the exact RPMs.. Trying to guess from the tacho is hard.

Thanks for this write up. I am about to tackle this but noticed they have listed 2 part numbers for OEM and wondered if theres a difference anyone is aware of between the 2. The description also doesnt match 100% saying IAC.

My vehicle is an 03 Type S.216022-P8A-A03
Valve Set, Rotary Air Control
216022-P8A-A02
Valve Set, Rotary Air Control

16022-P8A-A03 is what I installed in my '03 TL-S last year.

Excellent write-up!
If someone is interested in seeing how my old IACV looks on the inside after 19 years of use, I've got those 5-sided bits so I can take it apart and post pics later.
Just ordered the new IACV for like $55, threw in a new throttle body gasket as well for another $5. Free shipping thanks to Amazon!

I replaced my IACV with the AC229. The original IACV hadn't completely failed but the car sure ran rough, especially with the AC running. The new IACV really helped! The idle is much smoother and things don't vibrate with the AC on... Thanks for the recommendation.

Nice! glad it helped!

Harbor Freight Small Space Ratchet
 

https://cimg4.ibsrv.net/gimg/acurazi...8469f320bb.jpg
https://cimg1.ibsrv.net/gimg/acurazi...e4eab5bc18.jpg
I got lucky and was able to remove the 2 screws upside down without removing the throttle body. This little ratchet costs about $4. I used a small mirror to view the gasket which was in place and reused.

Thanks Skirmich for your thread!

I replaced my CLS6's OEM Denso MX136800-1012, after 160k miles, with the AC229 and the car is back to idling normal.

$59.29 shipped from rockauto.

The only difference I did notice, though, is it (the AC229) acts like the old OEM one, on a cold start/hot start, and will idle initially just above 1000rpm, then settle back down quickly to around 750-800rpm. The OEM one did the same thing over the years.

My original Denso though was marked MX136800-1012 where yours was a 1368091011. :shrug: :thumbsup:

I was wondering if this would be possible, but figured there wasn't space since nobody mentioned doing it this way.

I've ordered a new IACV and also the TB gasket, but not looking forward to detaching and reattaching everything, or scraping gasket and prepping surfaces. Turns our I already have one of those ratcheting low profile screwdrivers. Maybe I'll give that a shot first.

If this works: respect!

I didn't fully grasp what you meant about viewing and re-using the gasket. After some hassle, I got my IACV off with this ratchet ,but I removed the gasket and used the new one with my new part. Had I left the old gasket in place, I could have simply installed the new IACV and been fine. But after pulling off the old one, of course I couldn't get the new one to stay in place in defiance of gravity.

So I wound up taking the throttle body off anyway and having to spend the time to remove the baked on original 20 year old gasket :(

At least I know I have a good IACV gasket in place, I would have wondered if the old one was actually good (it was, after being off for a few minutes I could barely tell it apart from the new one).

I think I've got a vacuum leak somewhere, because the car idles a little high, but drives and behaves well except after driving for a while, it will surge between 1000-1500 RPM every 2 seconds only if its in park. If any load is put on by AC or by putting it in gear, the idle goes normal.

Perhaps I have a stuck open PCV valve. I'll check/replace that since it is dirt cheap and easy to access.

For the next person.

Turns out my problem was the new aftermarket IACV was crap. After wasting many hours trying to find a vacuum leak, replacing gasket, and replacing EGR and PCV for good measure, I cleaned the original IACV and put it back in to replace the aftermarket. Problem solved.

Brand was YCT and seller YCT Auto. I've given them 1-star. I ordered from them because they were the highest rated that had the fastest shipping.

Frustrating since the shortcut would have totally worked and would have only cost a few dollars for a bottle of throttle body cleaner. I could have left the gasket in place, cleaned out the original IACV, and put it back without ever removing the throttle body.

murky, just curious, I understand the part about 'highest rated' and 'fastest shipping'; however, why would you opt for an IACV other than what the OP recommended in the Standard/Intermotor AC229?

How much of a difference in price was the YCT brand vs. the Standard/Intermotor AC229 that compelled you to make that choice?

I tried the very same thing and it worked for like, 3-4 days and then the fluctuating idle returned. :ugh:

While I hope you do not encounter the same fate, with your cleaned original IACV, you still might end up getting a new one. If so, IMHO, don't bother with any other 'brand' then the Standard/Intermotor AC229. :thumbsup:

I got the off brand because it was Wednesday or Thursday and I was going to be working on it on the weekend. I needed something that would arrive Friday. The Intermotor would not have arrived in time. I also didn't know yet if I needed a new one. Not my car, didn't have time to do troubleshooting in advance. I figured it was inexpensive enough ($36) that I'd just swap it pro-actively, or at least have on hand if I determined it was needed.

I've had many good experiences with aftermarket parts in the past (although it seems to be getting much worse) with poor accountability and fake reviews on Amazon.