Step By Step Instructions For Iacv(idle Air Control Valve)/isc/throttl

[Lidorider]

Thanks for the great post, awesome detail.

The whole process only took 2 hours and cost about $5 for the carb cleaner. I sprayed all the screws with WD40 and gave them a crank with lock tight pliers before ever touching a screwdriver to them. This completely eliminated any worries of stripping the screws. There was no need to replace any of the gaskets either, they were in great condition. Truck started rights up and runs great now.

[mjsparth23]

second screw the one over where I took out the electric cable on the coil is stripped, got vise grips, pb blaster. nothings doing. any advice?

[Bio4x4]

Thanks for the Awesome post!. Wife's '95 es300 w/175k had the same "start/die symptom for the last week or so after the car was warm. Took the IACV off but also couldn't get the 4 screws out....even with my dad's old hand impact driver and a #2 (Only got 1 of the 4) stripped em all!!. Said forget this and just squirted out all the holes and butterfly with the right cleaner, blew everything out and put it all back together, all in about 40min. Started her up with no gas or rev and she purred right to an idle. Hope this is a long term fix as i'll do it again in another 100k or so. Got photos if anybody needs them for the early ES300.

Cheers!

[lexus0239]

Thank You...Thank You.....Thank You.....With your instructions and pictures made the job easy to do and what to expect.....one of the two brass screws had a bad time getting it out...used needle nose vise grips to remove it...what I would suggest is to retap the holes if the screws do not go in easy. once again Thank You ...Thank You ....thank You

[russki1]

how far doe the magnetic shaf turns? does it make a full 360 degrees turn? mine only turns about 90 degrees...

thanks in advance

[getitsold]

I totally appreciate all the helpful posts on this board. We got out Lexus back in May from a client who sold it to us cheap. One day after we bought it the transmission went out (2700 bucks). A month later a bad ECU (I found on ebay for 170). Now I have this IACV issue. I am going to take this apart once I have time and clean it out. The car didnt start the last two days and I narrowed it down to this part today using this board to troubleshoot it. The little 'pencil' tip was stuck when I tried to turn it but after twisting it a little it began to spin easily. I put it all back together and car started right up. I am guess it must be gunked up in there so I am sure I am going to have to dig back into this mess again soon. Seems very straightforward and again you made it extremely easy!!!

If you ever have to replace the door switches on the driver's side i could use some help there too. It seems like this car is haunted with issues!!

ALmost like my Jeep Grand Cherokee with all it's inherent bugs!

Thank God for this forum because it seems as if everyone has the same issues!!!

John

[moneysam83]

hi i have a 95 es 300 and i wanted to know if anyone did a step by step on the iacv on this model

[es300fan007]

nice DIY . i am going to try it as soon as the gasket arrives. also my problem is that the 2 screws heads came off (very sad) and i think it will be hard to remove it with extractor tool. so i wont remove them but if i were to just clean the IACV ( below the TB ) surrounded by the gasket part with throttle body cleaner then it should clear up the issue right? i hope so.

[PaulS]

I had the same problem with the screw. Luckily, a mechanic down the street from my house gave me a used screw from a pile of old throttle bodies/IAC valves that he has been replacing on vehicles that have the same cold-idle problems!!! Your instructions saved me a bundle of $$$$$!!!

When I finished cleaning out my IAC and got it back together, it worked better than ever. Now I give myself whiplash every time I step on the gas :) Is it normal to experience stronger acceleration from a stop? or has the throttle body just been way overdue for a cleaning for a very very long time?

Many thanks!

[Gedty]

Thank you Thank you and Thank YOU AGAIN!!!

The only thing I would add to your step by step is to remove all gaskets so you dont get carb cleaner in them. I use a toothpick to carefully pry them out. Also, coat the gaskets lightly with oil when putting everything back together.

No more check engine or traction control light

I used an impact screwdriver to remove the intake body. Worked like a champ. Then used a vice grip on the rest as to not damage the screws. Left some jaw marks on the screws, but the philips heads have no damage.

Lexus ES300 99'

[jay.syed]

great instruction, now my car runs like new. thank you

[DesertBighorn]

I started our RX300 to pull it into the garage to change the oil. It died when I put it into reverse and then wouldn't start unless I kept my foot on the gas. I changed the oil, same symptom. One Bing search and I found this post. After a trip to the store for a larger screw driver, some cleaner and then a couple of hours under the hood and bingo, we are back in business.

Thanks!!!

-Doug

[green-rx300]

Worked like a charm! Thanks!

[goldenrx300]

My dad used your instructions to fix my lexus and now it runs great! Thank you for saving me a lot of money!

[Tomopets]

I'll be trying it this wkend, thks for write up

[GoldenStateSilverSport]

Guys- It's been awhile since i visited this forum, but wanted to say, I just performed this again yesterday! Car is working great - I can't believe my post on this was 6 years ago!! Glad to see it can help soo many people.

As usual, it was tough getting the factory screws out but that's where the grip locking pliers can help!! Cheers, Gang!!

[LeddyGee]

Another SUCCESS STORY here. Holy crap, Golden, can't thank you enough for taking the time to put this together. Here's the deets, as the kids say.

2001 HIGHLANDER (V-4) w/ 120k miles.

I have very little experience with "car stuff" but am somewhat handy.

Have had infrequent random problems over the past year or so:

1. Surging idle.
   
2. Won't idle at all.
   
3. Won't start. (wait 30 mins, try again)
   

Usually these issues would pop up and last for a few days and then disappear. Nuisance but I lived with it. However, for the past 2 weeks the two-foot-shuffle finally got to me and I finally dove into this project. The whole project took me about an hour...

• Left the throttle body attached and only removed the IACV.
  
• Almost stripped one of the bolts (Phillips) but was able to remove with vice grips.
  
• Found that the "pencil" valve thing inside was indeed binding. (got excited at this point)
  
• Cleaned the IACV as well as I could.
  
• Re-used the old gaskets.
  
• Reinstalled everything and...SUCCESS!!!!
  
• Shop quoted $650 to replace the IACV. ("Suck it!")
  

One question, however. I was unable to remove the cylindrical internal "pencil" valve thing out of the housing. I pushed and pulled very hard and no dice. I saw pics elsewhere (HERE) of this part completely removed during this process. How do you get that thing out? I was able to clean it a bit but not as well as I would have liked.

Golden, again, I can't thank you enough for doing this for the community. You certainly paid-it-forward and I'm extremely grateful. And though you have 15 pages of others thanking you for the same I suspect that there are hundreds (thousands?) of other folks around the world that used your instructions successfully without posting results back here. I'm sincerely grateful. I saved a crapton of money and learned a lot in the process.

-Leddy

[so, how to remove the valve as shown in the pic below? (ignore magenta circle) BFH???]

[boxer04]

hey thanks for this post!! i just performed this on my 2001 rx300 (98k miles) and it now runs like a champ!! had the symptons of stalling after start now its totally gone. took me about 2 hours. thanks again!!

No problem. glad i could help!

Many thanks for your instructions. My 2001 rx300 would not idle & after the cleaning,smooth as silk, and to think that 20 yrs. ago I would have never attempted this. Oh what a fasinating modern age in which we live,thanks again

[ja8669]

Great work. I can't wait to try it on my wife's RX 300. I used to work on cars when they still had carburetors so this should be fun. Too bad I have huge hands. Should have bought a truck!

[neilrut]

this was a real life saver. I don't mind paying the money to have my car fixed but 2 mechanics could not fix my idle problem. I even pointed this thread out to one of them and still no results. I have 0 experience fixing cars but I followed these steps very carefully and my car is running as if it were new! I performed the IAC cleaning about 2 weeks ago and not even a hint of the problem still exists. What a relief! Thanks for posting this.

[TopQuark]

Just cleaned my IAC valve, my RX is running again. It helps to loosen the screws with vise grip first. I did not install the valve correctly the first time. The car will RPM will go up and down.

I took valve out and reinstall it correctly and making sure both valves opens at the same time.

Thank you very much to all !!!

Well, it happened to me too. The idle cycles between 2000 to 3000 rpm and it turns out, the throttle unit was not mounted correctly. The throttle spring that opens and close the valve is not seated correctly. I can tell by the gas pedal. It feels light and does not engage well.

As stated by ml30306 in post# 170, if you want to replace the 3 screws for the throttle unit for the RX300, get 2 units with bolt size M6 with 1" pitch and length of 60mm and another one with size M6 and length of 28 mm also with 1" pitch. Diameter of the screws is ~5mm.

I did not replace any of the gaskets and O-rings.

[rusmosey]

Thank you very much!

[a_r_justice]

Much Thanks! My 2003 rx300 idles now.

[2001Lexusrx300]

I started our RX300 to pull it into the garage to change the oil. It died when I put it into reverse and then wouldn't start unless I kept my foot on the gas. I changed the oil, same symptom. One Bing search and I found this post. After a trip to the store for a larger screw driver, some cleaner and then a couple of hours under the hood and bingo, we are back in business.

Thanks!!!

-Doug

Hey, How did you put the throttle body back on? I got it out, cleaned it, by now it's a bit difficult to put it back in. I can get it in, but the screws wont match up with the holes.

[ealexv]

I just finish doing this on my dad's avalon 02 i will post later to check on them if they stop having the probrem wirh there car