fluctuating idle while stopped and in Drive (A/C on)... idles too low?

I started a thread a while ago about my '07 V6 that I picked up a few months ago. When I purchased it there were 65K miles on the clock, and now I'm up to 73K. The only issue that I cannot seem to fix is the low idle while stopped and in Drive (usually in traffic of course). I do notice that the A/C does have some influence on the fluctuating idle but I feel like when it drops down to 500 RPM, it's a bit too low because you can feel the engine vibrate in the steering wheel and in the seat.

Here is a video of the fluctuating idle: 2007 4Runner idle with A/C on - YouTube

I used to have an '04 V6 and I don't ever remember it idling this low or being able to feel it when it dropped down with the A/C on. Is there anything I can do? So far I have:

-replaced the spark plugs
-replaced the air filter
-cleaned the MAF sensor
-cleaned the throttle body intake

I am wondering if a higher-octane fuel would help?

Could you run this quick test for us?

At idle, hold the brake while in drive like you would be at a stoplight and then rev the engine to about 2500-3000 RPM and then let off the gas. See how long it takes for the idle to stabilize again, and if the RPMs drop very low and then bounce back up again. It could indicate a failing IAC (Idle Air Control) Valve.

BlackWorksInc said:

It could indicate a failing IAC (Idle Air Control) Valve.

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Come on bud, you should know this! It's an '07. It has an electronic throttle body. No more IAC motor.


To the OP: Did you reset the computer after the TB cleaning?

Meh.

It isn't hurting anything.

Your vibration is simply resonance frequency. The v6 is a more "viby" engine. Not for any reason other than they through a huge counter balance on the v8 that makes it smooth.

At 500 rpm's, your truck just hits that vibe and you feel it. It is fine. I wouldn't speed much time trying to track this down. Somethings are just things.

ChaosStarter said:

Come on bud, you should know this! It's an '07. It has an electronic throttle body. No more IAC motor.


To the OP: Did you reset the computer after the TB cleaning?

Click to expand...

Yes, after doing everything listed above I disconnected the battery long enough to reset the computer. It improved the idle for a while but it seems like it was only temporary (or it was a placebo effect)

I don't think that it will ever stall but to me it would make sense for it to never drop below 600 since it's perfectly smooth at anything above 500 RPM.

DC runner said:

Meh.

It isn't hurting anything.

Your vibration is simply resonance frequency. The v6 is a more "viby" engine. Not for any reason other than they through a huge counter balance on the v8 that makes it smooth.

At 500 rpm's, your truck just hits that vibe and you feel it. It is fine. I wouldn't speed much time trying to track this down. Somethings are just things.

Click to expand...

Ha you may be right. And maybe the real solution is to get a 4Runner with a V8.

I loved my '05 V8. I should have never sold it.

ChaosStarter said:

Come on bud, you should know this! It's an '07. It has an electronic throttle body. No more IAC motor.


To the OP: Did you reset the computer after the TB cleaning?

Click to expand...

Doesn't mean the throttle body couldn't be starting to fail. You're right there is no actual IAC valve anymore (We all make mistakes sometimes thanks for correcting me) But the throttle body will still mimic an IAC. I have seen this on a couple vehicles that use a throttle body to mimic an IAC (GMC Envoy was the most recent)

BlackWorksInc said:

Doesn't mean the throttle body couldn't be starting to fail. You're right there is no actual IAC valve anymore (We all make mistakes sometimes thanks for correcting me) But the throttle body will still mimic an IAC. I have seen this on a couple vehicles that use a throttle body to mimic an IAC (GMC Envoy was the most recent)

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That I do agree with you. :

I've done a few of the older V8 throttle bodies from TPS issues (before they went to a full electronic throttle body). Damn, they're quite expensive.

Pretty much most newer cars do use the TB as an IAC because it's easier for the computer to control with less components.That's why not only keeping the TB clean is important but reseting the computer to compensate for the cleaning.

ChaosStarter said:

That I do agree with you. :

I've done a few of the older V8 throttle bodies from TPS issues (before they went to a full electronic throttle body). Damn, they're quite expensive.

Pretty much most newer cars do use the TB as an IAC because it's easier for the computer to control with less components.That's why not only keeping the TB clean is important but reseting the computer to compensate for the cleaning.

Click to expand...

When did this change on the 4th 4runner?
Does my 04-V6 has IAC or no? TIA.

Derek said:

Yes, after doing everything listed above I disconnected the battery long enough to reset the computer. It improved the idle for a while but it seems like it was only temporary (or it was a placebo effect)

I don't think that it will ever stall but to me it would make sense for it to never drop below 600 since it's perfectly smooth at anything above 500 RPM.

Click to expand...

after disconnecting and connecting the battery......to have a smooth idle..u need to start the car and leave it in park for about 6mins...so the ecm can relearn the default adaptation table