Lexmex

The wire should come off easy, but sometimes it is a hard tug. The hose is very simple and pulls off easily.

blah2u

thanks lexmex, i'll give it another go later tonight.

nghiaho58

Thanks Lexmex for the great post to fix this annoying problem. About a year ago, I followed your instruction and was successfully fixed the problem of my 2000 RX300. Yesterday, my 2003 ES300 with 128K miles has very low idle and sometimes it went to zero. My question for you is can I use the same procedure on the ES300?

Your advice is greatly appreciated.

Nghia Ho

Lexmex

Yes, though it will look a bit different.

grizybaer

When i view the post, i dont any of the OP's pictures. is anyone else having this problem?

Lexmex

Welcome to the Club.

They come up fine for me, can you see the photo I just attached?

LALexusOwn

I was having low rough idle problems only when my RX was cold. So, I decided to do this DIY. Now, I'm having a rough low idle all the time. The idle in park is 100 RPM or less, then after a minute or two it dies completely. In Drive, the same thing. I went for a drive after and under 20 mph, it dies. I took everything a part and put it back, I thought I might of missed something like the lower hose, or didn't seat a connector tight enough.

After putting everything back together, it is the same. I'm sure I got all the hoses I disconnected and all the connectors are tight. Does anyone have any idea?

I tried replacing the battery with a new one, I thought it might be a charging problem. That also didn't help. I don't have any Check Engine Light. It seems to me that if it was running good warm before, this DIY should have caused any idle problems. Any ideas would be appreciated. If not, I'll need to drive with two feet to the dealership on Monday.

Lexmex

How's your air filter? Also have you cleaned the PCV valve? Sometimes clogged fuel injectors can also cause the low idle.

LALexusOwn

Thanks for the suggestions Lexmex. My air filter is new and it doesn't look bad at all. I have cleaned the PCV valve and the hose. I also added some fuel injector cleaner additive. I don't know if that actually helps clean injectors or not cause I didn't notice a difference. So, today I pulled the whole throttle body and cleaned from the instructions you posted.

"Throttle body removal https://www.clublexus.com/forums/rx30...ark-plugs.html"

I used Berrymans B12 Chemitool and hosed all the nipples and wiped down the entire TB inside and out thoroughly.

It now only idles low (300 RPM) when warm in both park and drive.

Cold it will die only when I accelerate, then let my foot off the gas and brake. Seems like an idle control issue.

About 10 miles after the full throttle body cleaning I got a CEL and threw codes P0171 - System Too Lean Bank 1 and P1130 - Air Fuel Sensor Circuit Range/Performance.

So I reset the codes to see if it would CEL again. I drove another 115 miles tonight and just got home. Coming off the freeway at the last leg I got a CEL with P0505 - Idle Air Control System.

I'm thinking that the IACV is just bad and needs to be replaced. I'm going to try do my daily 150 mile commute tomorrow and see what new CEL codes come up along the way. Does anyone know if these IACV's just go bad?

Lexmex

The IACV can go bad after a while. Over the years, I've also seen people have an issue with that tiny little rubber ring that comes off when you open the the IACV valve (to turn the smooth **** when you are cleaning) and that can cause some issues.

Sometimes the accelerator cable can also get caught or stuck, and that's one of the reasons I tightened it many years ago, https://www.clublexus.com/forums/rx-...se-advise.html

Also note one other area that should be cleaned,

https://www.clublexus.com/forums/3049645-post45.html
https://www.clublexus.com/forums/rx-...t-yours-4.html

LALexusOwn

Hi Lexmex, what issue with the tiny little ring? I noticed mention of it, but I think I lost mine cause I know for sure that there wasn't one.

Anyway, I tightened the accelerator cable and cleaned that plastic piece too. It is still idling low. Symptoms since yesterday are this. I drove my commute and other than driving with two feet, I didn't get any codes/CEL/ or engine dying after it was warmed up. So, the wifey drove it today, she complained that it kept dying every minute, the A/C didn't work, power steering wouldn't work, it wasn't shifting right and jerky (all idle issues). Boy did I get an ear full. And the CEL came on for her. Just tonight I pulled the code and it was P0505 again. So, I'm going to drive it again tomorrow and think about either buying a new IACV online or dropping it off at the dealer. Thanks so much for the help and advice.

Lexmex

Well the little ring thing is just after you take off the screws to remove the cover (black piece in the picture above with electrical connector plugged into it) to the little screw that you can turn. I don't think I have pictures of that little rubber ring, but it's caused issues for me when I forgot to put it back on. Someone else on the forum might have a picture of this ring as I probably won't have a chance to get to it given my schedule.

LALexusOwn

Hi Lexmex,
"it's caused issues for me when I forgot to put it back on"
What kind of issue did you have when you forgot to put it back on?

I know that what your talking about so no picture required. And I know I don't have one in there? I have no idea what happened to it from pulling the IACV on and off so many times. So, I decided that since I know the little black ring is gone I'm going to buy a new one from Rockauto.com. I saw it mentioned in another post. I'm just hoping that the full IACV replacement will fix my problems.

Lexmex

I had some minute idle issues after that...basically small idle fluctuations instead of staying around 700 to 800 rpm in park. Wasn't great, but I do know the rubber ring needs to be there. I remember someone else reporting on this same issue with the rubber ring a few years ago, but can't remember who it was.

LALexusOwn

Thanks for all the help Lexmex. Just to update my issue. I got the new IACV from www.rockauto.com and took some pictues of the old and new one side by side. You'll notice the old one on the left is filled with carbon in the right side air flow valve. The old IACV little magnetic drum would rotate in full 360 degree plus. The new one only would rotate the 1/4 or less turn just enough to open and close the valve. So, I guess the 360 plus rotations were the cause of my issues.

Further below is a picture of the new IACV with the black electronic cover taken off with the black inner washer seated into the casing and you can see the inner bronze wavy washer just behind the black washer.

for $160 for the part, I don't think it is so bad. My idle is now a perfect 1200 rpm cold in park and 750 rpm cold in drive and hot. It beats paying $600 for parts and labor at the dealership.