Welcome to CL. Please read the whole thread. You will find various solutions. Just make sure you buy new screws for assembly.

Salim

 

As long as I can remove the screws, I have new screws to replace. What is best way to do it?

Thanks

 

I use a hammer to seat the screw driver.

You can use slender locking pliers to grab the head.

I tighten the ones that have been loosened to relieve tension on the stuck one.

Salim

 

Thanks to all who contributed to this thread. As listed in my thread only a couple weeks ago, I was having symptoms that pointed to my IACV. Today, I followed this DIY and (believe) I successfully cleaned my throttle body and IACV.

After removing the hoses, I saw the right TB was a little more yellow than the pipe closest to the firewall (where the IACV little hole thingy is). I made sure to spray well, and was very relaxed once I noticed the spray removes the gunk immediately.

Long story short, I made sure TO DETACH THAT DRAIN HOSE and then after I even stuck a paper towel up to get all moisture out because I really didn't feel like experiencing any burn off.

Started the car, and when I figured she should've cranked, I gave her some gas and she started right up. No burn off exhaust or smells.

Has run fine, just under 1k rpm ever since.

Changed air filter right after. Also, cleaned MAF and reset that fuse yesterday.

I'd say, for having not done work on my own car ever, this DIY was not only easy to follow but was quite self explanatory for someone who still has no idea of the process air takes through the box the TB etc etc...

Oh, and I didn't have any of the tools listed, so I bought them all and used them all. Except shop towels..I have paper towels!

The vice grip was definitely necessary.

One important point, I remember turning the IACV before I started cleaning with maybe a little feedback. Having not paid much attention, only now remembering what I felt, I can tell you that after the cleaning, that little valve turned quite easy.

Also, the O ring. Lol...glad I read that far into the thread. I noticed it as soon as I loosened the screws and made sure I kept an eye on it through the process.

So, to all, thank you.

 

I am having to do this cleaning more frequent now. Is there anything else I can check to help stop or slow it down a bit ? (1997 ES300)

 

A quick spray of pb blaster and an impact screwdriver is perfect for those screws.
Only $8 from harbor freight.

http://www.harborfreight.com/impact-...ase-37530.html

 

Thank you for this post, just did this on a '99 ES300, 189K. I had been in here before, having previously replaced the original split 3 rubber air coils.

On the ES300, pulling the complete airbox allows good access to the screws,
happily no problem there. I had an old IACV to look at, as this is a previously replaced part. Strangely, I thought the original IACV, which I still have,
had more "magnetism" then the Aisan replacement, which I was cleaning.

I had the recurrent cold start problem; opening the 2 screws showed me the shaft was "catching" on the 90 degree rotation. I pulled every possible hose in this assembly, and sprayed CRC throttle body cleaner a couple times, as well as cleaning the venturi and butterfly plates.

This was one of the simpler CL preventative maintenance efforts.

The PCV replacement was a horror show unto itself, unfortunately...

I will post a followup on the car's cold start response in a couple days...

 

Thanks to this post, it has helped me numerous times when battling this idle air control valve issue. I have a 2000 RX300. The first time I had an issue with the idle air control valve was when the car had about 65k miles. Fortunately, I was able to bring the car to the dealership and get that part replaced since I had an extended warrranty. After my warranty expired, I was on my own. But that's ok, because this site's been a godsend of knowledge.

I think I've cleaned out my idle air control valve and throttle body (spray only with parts still on car) about three times since. I now have about 177k miles on my car and just recently when I started the car it would just die. So I figured it had to be the iac (idle air control) again. While researching online, I found a video that suggested that after you remove the rubber hose from that little metal piece that connects to the idle air control valve (circled in red), then you can simply plug something into the metal piece (circled in orange), I plugged mine with a small piece that I cut from a pool noodle, almost like a piece of foam, but you can also use a piece of tape I guess. Then I proceeded to spray CRC Throttle body Cleaner very generously into the blue circle 1, probably about 5-7 seconds of spray. While the fluid eventually did leak out elsewhere, I'm hoping that with the foam plug that I used to plug up the metal piece did allow the spray to stay longer inside the iac than without using the plug. Then I proceeded to spray inside the iac (see blue circle 2) and spin the pencil tip thing vigorously for about 1 min. Then I would repeat this step for about 10 times. Spray into blue circle 1 for about 2 secs, then spray into blue circle 2 for about 2 secs (try to spray into the metal shaft that goes into the inside portion of the iac), and spin the heck out of that pencil thing for a minute each time until you repeated this process for about 10x.

See second picture with red arrow. Spray directly here along the metal shaft of this pencil thing and spin away.

I noted that in the past when I did this, I would only spend about 2 minutes cleaning the iac and just thought that was enough. The pencil thing would spin easier, but now that I'm thinking back, it would still stick a bit when rotated through its complete range. Now when I did this cleaning using the above method that I posted, the pencil thing spun so much freer than in the past. It now felt so free that if I simply blew on it, it would probably spin. Hope this helps someone.

Cheers!

 

Thanks, SandyBeach for this tip. I've always done it the same way you did before. I now have to do it again. Last time I cleaned IACV was about 26 months ago, about 23K miles later. Not bad I would say.

 

i just did this DIY on my iacv. However, can tell if mine is bad or not. Once I removed the motor part, I played and sprayed the magnet/****. Mine rotated smoothly, but only about quarter or half turn before it hit a stop each way. Is it supposed to stop like that or just spin 360 freely.
Also, my idle is still jumping around some. How can I test to see if motor is working right or if it is just flapping back and forth.
No codes being thrown.
Also
Wondering if jumpy idle could be Throttle position sensor or MAF? Do notice idle jumping more when AC is on.
Thx

 

Rotation should be about 90 degrees. The slug allows progressively more air and it is not supposed to spin round and round.

Did you clean out the TB orifices and pipes. Also how old is the air filter.

Salim

 

Salim,
I just cleaned the idle bypass holes and quick wipe down of butterfly gate. I had the whole throttle assembly off when we installed the new RX330 valve cover and PCV valve. Once reassembled is when this jumpy idle started. Thought we forgot a vacuum hose or something but I checked all of them.
IACV does rotate freely for about 90 degrees. So I think valve is OK. But is there a way to test valve motor to see if it is working right? Or are there other sensors that could be sending false signals.
Does not jump when first started. Only starts once warmed up a little.
More pronounced when AC turned on.
I did just clean the MAF while I had everything apart just now. But cleaning did not seem to help much.
Air filter is pretty dirty.
Any thoughts or recommendations to check next?
Thx
Charlie

 

There may be a vacuum leak or a disconnected hose. Make sure you install all new gaskets if you removed/separated some parts. You may have to disassemble and re-assemble the IACV.

do change the air filter.

Salim

 

Did this today after my 2000 RX had had several stalls when first starting in the morning over a period of a few weeks. Very simple fix with the great instructions in the thread, and the only real issue I encountered were the two screws on the IACV. I found that the screwdriver was useless in loosening them even with the hammer tap trick. The vise-grips did the trick and then I used the screwdriver. I think now I could do this in 15 minutes the next time, if there is a next time.

When I first cranked the engine after the cleaning, my idle RPM started at about 1800, but it slowly and steadily dropped and reached about 900 after about a minute. I didn't do any revving of the engine, just let it idle.

I have to say the car seems to run better now. Has anyone seen any improvements in gas mileage after doing this?

 

Well, after two tanks of gas I do see an improvement of at least 10% in my typical city MPG after the IACV fix. The first tank was 18.8 and the next was 18.2, which is excellent in my experience. Note that this is the actual MPG, not the car computer value. As more data is accumulated I will update further.