Starting/idle Problem Rx300

[RX300Billy]

My Rx300 has exact same problem, so I got read the forum and took out the 2 air intake hoses and the IACV locates right under them. I took out the two screws and cleaned the inside with the throttle body cleaner. The problem went away, so here is the pictures I took (IACV is the black piece with the two screws, one of them has the yellow dot on it).

Hope this help somebody in the future.

Thanks for help. My 01 RX300 had trouble with idle and low rpm idle too. Cleaned the idle control valve as instructed and works great. A little note for first timers, use a #3 philips screw driver for the 3 screws on the throttle body. Be prepared for coolant to leak out, I had about a quart of coolant leak from the hose line. Maybe it was because the car engine had been run. I did have to buy 3 new screws from the dealer, as mine were a worn out.

[MistahX]

My Rx300 has exact same problem, so I got read the forum and took out the 2 air intake hoses and the IACV locates right under them. I took out the two screws and cleaned the inside with the throttle body cleaner. The problem went away, so here is the pictures I took (IACV is the black piece with the two screws, one of them has the yellow dot on it).

Hope this help somebody in the future.

Thanks for help. My 01 RX300 had trouble with idle and low rpm idle too. Cleaned the idle control valve as instructed and works great. A little note for first timers, use a #3 philips screw driver for the 3 screws on the throttle body. Be prepared for coolant to leak out, I had about a quart of coolant leak from the hose line. Maybe it was because the car engine had been run. I did have to buy 3 new screws from the dealer, as mine were a worn out.

Ok so I followed the instruction posted by 'oldrx300' and the problem is still here. Now I noticed in the picture that 'RX300BILLY' posted he took apart the whole assembly not just the IACV. Is this what I'm supposed to do? Any help will be greatly appreciated. Thank you.

[01 black on black on 18s]

Let me try and clarify all the confusion here. A lot of people are confusing the IAC valve with the black plastic stepper motor held on with 2 screws. Removing the black plastic stepper motor will do absolutly nothing to fix your problem. In order to fix the problem you need to devote aprox. 4 hours to remove the aluminum piece that the black plastic stepper motor screws to. On any RX with over 80,000km (50,000mi) the screws will be so tight that you will have to remove the entire right side throttle body (possibly the whole TB)in order to remove the screws. Once this is off then you can remove the 4 screws that hold in the actual IAC valve and clean it properly.

Yes high idle and low idle can be caused by the same dirty IAC valve. Hot or cold your idle should never go over about 1800RPM. Fuel injection eliminated the need for high idles.

Dan.

[Roadkillav8r]

My problem is slightly different in that after start the idle is high (1200+ RPM) and it takes a considerable amount of time before it idles down enough that I feel like I can put it in gear. Is that still an IACV problem or something else? Thanks

[Odstar]

Thanks for this thread! It saved us hundreds in repair bills! I just want to add that when removing the throttle body to access the IACV make sure you put WD-40 or PB Penetrating Catalyst on the 3 screws because those factory tighten screws are a b@#%h to remove. I replaced the screws that were stripped at my local hardware store. Make sure that they are automotive screws. There are lock washers also on these factory screws so make sure you get replacements for those too. Also make sure you get the right tight fitting screwdriver. I repeat those factory screws will strip if not properly removed. Now when you are able to remove that throttle body there is metal gasket behind that throttle body so make sure you put that aside. hope this extra info helps. Thanks

[01 black on black on 18s]

...so after posting that "how to" 3 posts back my RX still wouldn't idle after cleaning the IAC and reinstalling it! How stupid do I look now! So here's what I did; removed the IAC again this time I noticed that the valve seemed tight, like the bearings that hold the shaft were dirty, so I was able to remove the steel pressed in cap over the end and could now spin the shaft 360 degrees, so I soaked it in penetrating fluid until it spun like it was brand new, I reinstalled the IAC (yes, in case you were wondering I marked the steel pressed in piece and it went back on exactly the same way it came off)and STILL HAVE THE SAME ISSUE!!! I have another RX that I bought off a guy from California and am waiting on the title and ownership so just to eliminate a possible bad throttle body I switched the throttle bodies and now the idle problem is fixed. I still however need to fix my California RX! Anyone ever run into this? The IAC is pretty simple once it's apart so I don't think replacing it will solve the problem but I am open to suggestions at this point!

Dan.

[Halim]

How much you paid for throtle body and from where did you buy?

[01 black on black on 18s]

I didn't buy a new throttle body I just swapped it with another RX300 I have.

[Kevin Campbell]

my 01 rx300 wont start unless depressing the accelerator. after it starts it still will not idle, runs great when normal driving conditions. but as soon as foot comes off accelerator vehicle dies...could this be the Idle speed control motor??

[salvagedoor]

My Rx300 has exact same problem, so I got read the forum and took out the 2 air intake hoses and the IACV locates right under them. I took out the two screws and cleaned the inside with the throttle body cleaner. The problem went away, so here is the pictures I took (IACV is the black piece with the two screws, one of them has the yellow dot on it).

Hope this help somebody in the future.

[salvagedoor]

My Rx300 has exact same problem, so I got read the forum and took out the 2 air intake hoses and the IACV locates right under them. I took out the two screws and cleaned the inside with the throttle body cleaner. The problem went away, so here is the pictures I took (IACV is the black piece with the two screws, one of them has the yellow dot on it).

Hope this help somebody in the future.

My Rx300 has exact same problem, so I got read the forum and took out the 2 air intake hoses and the IACV locates right under them. I took out the two screws and cleaned the inside with the throttle body cleaner. The problem went away, so here is the pictures I took (IACV is the black piece with the two screws, one of them has the yellow dot on it).

Hope this help somebody in the future.

I read the post as well and followed it through the entire steps and cleaned it thouroughly with excellent results and did not replace the O ring or gasket. Definitely beware of the bent washer inside the O ring. If it falls and doesn"t hit the ground it could be tricky finding it. Also, keep your coolant hose higher than your radiator when you pull of the throttle assembly to prevent it from leaking and having to replace coolant. Thanks for this information.

[MABJAB]

My Rx300 has exact same problem, so I got read the forum and took out the 2 air intake hoses and the IACV locates right under them. I took out the two screws and cleaned the inside with the throttle body cleaner. The problem went away, so here is the pictures I took (IACV is the black piece with the two screws, one of them has the yellow dot on it).

Hope this help somebody in the future.

Be careful not to strip the two screws when removing them. It is challenging to break the factory torque to loosen those screws so find a very tight fitting screwdriver that will do the job. I am in the middle of cleaning my IACV myself..

I actually went and purchased hex head screws and replaced the phillips head screwa. Makes it easier to remove them the next time you have to do it.

[glennb1961]

Fixed mine on Monday, Labor Day, took about half an hour, hardest part was loosening the 2 screws on the idle control valve. The steps posted here are a great help. This is after talking to the local Lexus dealer, they said my battery was weak, and when I mentioned about the ICV they changed their tune to about $400 repair job. The service advisor said that their tech had to do the job because the ICV is not easy to get to. What a bunch of crooks.

[Fast Jimmy]

Jaru22

If your starter is just clicking and eventually starts (or not) it may well be the starter contacts. Toyota starters last forever, but the starter contacts wear out. Especially the positive contact. I had this happen at 76,000 miles on my 2001 RX300, and replacing the worn out contacts and plunger solved the problem. At 125,000 miles and still starting strong. Contacts are less than ten dollars and plunger is twenty.

[SrL]

I tried removing the 2 screws of the IACV but they are too tight ...next approach to spray and clean throttle body with tooth brush, clean the butterflies and all around and inside where chamber of IACV is.

Start car and IT WORKED! I spend $2 for cleaner and I save like $500 :)

[Kimmierose]

Hi I have a 1999 Lexus RX300 all wheel drive I changed the timing belt the tensioner plugs coil packs solenoids coolant solenoid timing solenoid oil control valve still rurns really bad   still will not stay running constantly stalls has no power and nothing's coming up on codes for anything else that is Miss or not working please I need help I have no idea what else to do or what else it could be I have checked all of the fuel injectors throttle body what else could it be please let me know,,,,

Thank you....

Edited October 18, 2019 by Kimmierose
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