Trouble With Very Low Rpm At Start

[Xerox]

Hi,

I have an '00 Rx300 which has recently started showing this problem occasionally.

When I start, the IDLE RPM is extremely low (200-300) and I can hear the engine differently. When I rev it up at, the sound is different and the rpm comes back to the same low with the dashboard lights turning on (like when you put the ignition in and turn it on before starting) but the engine stays awake with same 200-300 rpm :(

In these situations, when I turn it off and restart, it wakes up fine with about 1100-1200 revs and gives no trouble.

I have noticed it thrice in like three months. Anybody has a clue if this is bad plugs or something serious?

I'd Appreciate comments/suggestions.

[mehullica]

The idle speed control motor under the throttlr body needs to be replaced. Carbon builld-up.

[SKperformance]

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iacv

[lenore]

Welcome aboard Xerox, hope the advice helps you. I do not know your skill level, or if you do take it somewhere go to an independent that you can trust, or use Toyota instead of LEXUS> Joe Wilson would tell you the Same.

[bluestu]

In the past I've experienced various idle problems. Since I started using Seafoam Fuel System and Engine Cleaner every 3kmi., I have had no idle problems from either one of my RXs. You can purchase the product at Advance Auto Parts for around $7.

[artbuc]

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iacv

SK, I searched IACV and found all problems listed had to do with low idle indicating a dirty/restricted IACV. I have made several posts regarding my problem which is high initial fast idle rpm. Have you ever run into this problem?

[SKperformance]

artbuc make a new post with the detials of temp outside and the rpm , we can best answer you there.

thanks

[Xerox]

Welcome aboard Xerox, hope the advice helps you. I do not know your skill level, or if you do take it somewhere go to an independent that you can trust, or use Toyota instead of LEXUS> Joe Wilson would tell you the Same.

Thanks! :) I am not a hands-on guy and don't know much about inside the hood of Lexus much. I take it to a independent guy that I trust so will ask him and see what he says.

So I am definitely looking at probably IACV or throttle body (cleanup or replacement). how much should each of this cost approx.?

[GoldenStateSilverSport]

Welcome aboard Xerox, hope the advice helps you. I do not know your skill level, or if you do take it somewhere go to an independent that you can trust, or use Toyota instead of LEXUS> Joe Wilson would tell you the Same.

Thanks! :) I am not a hands-on guy and don't know much about inside the hood of Lexus much. I take it to a independent guy that I trust so will ask him and see what he says.

So I am definitely looking at probably IACV or throttle body (cleanup or replacement). how much should each of this cost approx.?

I am currently having this problem right now. When I start to my car, I need to gas it for a couple of seconds to keep it from shutting down, otherwise the car will just shut off if I let off the key. I had the throttle body cleaned in November, and they presure cleaned my injectors, however they did not clean the IACV since I am still having this problem. I called two Lexus dealerships and they don't "clean" the IACV, they only replace it for about $700. One lady said they only replace it cause if they clean it, it's only going to get dirty again which didn't make any sense to me. When I called the second Lexus dealership, they said they only replace it.

I just called a toyota dealership and they said they would clean the IACV for $99. When I explained to the service advisor why I am getting the IACV cleaned and the starting problems I was experiencing, he said that cleaning the IACV won't do the job. He'd prefer I take the car in and have it diagnosed. So, Im a little confused on what to do. Any suggestions? Does the advisor not know what he's talking about? And is Lexus out of their mind for not wanting to clean the IACV?

[bluestu]

I had the same problem for a while. I bought a can of Seafoam Fuel System Cleaner at Advance Auto and haven't had any engine problems since. I now add a can at every oil change.

[GoldenStateSilverSport]

The idle speed control motor under the throttlr body needs to be replaced. Carbon builld-up.

Are "idle speed control" valve and idle air control valve synonymous?