95.5-2004 Tacomas & 96-2002 4Runners 4th gen pickups and 3rd gen 4Runners

Idle Question

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Old Dec 6, 2002 | 05:49 PM
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From: SC
Idle Question

Hey guys,

Well I have noticed that since it has really cooled down here (as cool as SC can get), my idle seems to be quite a bit higher. Now I know that my rig will idle high until the engine has heated up to its optimal operating temperature, but once it has done that, it still seems to idle around 1000 rpm most of the time. However, during summer time and stuff like that, normal idle is 750-800 rpm. Any ideas? Thanks for the help-
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Old Dec 6, 2002 | 05:58 PM
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The ECT (Engine Coolant Temp Sensor) might be failing. Your thermostat might be sticking, also.

Those are what jump to mind.

My .02
Dr. Z
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Old Dec 7, 2002 | 06:26 AM
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From: SC
Thanks for mentioning the possibilities Dr. Any one else have any ideas?
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Old Dec 8, 2002 | 10:43 AM
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Cody, mine does this every year.
I just turn it down manualy to about 800 RPMs, and it's fine.

I turn it back up during warmer weather.

I am not sure either why it does this, could be the weather as you stated.

In fact I need to turn it down since we have got a lot colder here now, it's running a tad high.
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Old Dec 8, 2002 | 10:47 AM
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From: Yavapai County, Arizona
How do you turn it down? (if you can on a 95?)
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Old Dec 8, 2002 | 10:47 AM
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Again, I'm not sure if this is the same, but I know here in AZ, most of the older import cars do this as well, and just tuning the air/fuel scew on the throttle body clears it up for the winter months,and then the other way for the summer. Also smooths out the idle quite a bit.
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Old Dec 8, 2002 | 10:54 AM
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From: SC
Ya, maybe I will adjust the idle once I get home for the break. It seems that no matter how long I run the engine, it still idles a couple hundred rpm's higher. I know there was a great picture that someone posted of the idle adjustment screw....

Corey I'm sure you have it saved somewhere, right??
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Old Dec 8, 2002 | 10:57 AM
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Did someone say picture?

I love my digicam

Look inside the Tech folder for idle screw.
http://www.pnw4runners.net/tech/

Very easy to do.
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Old Dec 8, 2002 | 11:06 AM
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From: SC
I knew we could count on ya' Corey. Thanks.

By the way, just to be sure, have you noticed any negative side effects at all during the time that you have lowered the idle?


Oh ya, one last thing...where is the suspension round-up page? I can't find the link to it anywhere. Maybe I'm just a moron
:confused:
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Old Dec 8, 2002 | 11:50 AM
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During idle operation, the throttle valve is almost completely closed. Idle air enters the engine through an adjustable throttle air by-pass screw which varies the amount of air which can flow past the closed throttle valve. By turning this screw clockwise, throttle by-pass air is reduced, causing a decrease in idle speed. Conversely, turing the screw counter-clockwise will increase idle speed by allowing more air to pass the closed throttle valve.

On engines equipted with an ECU controlled ISCV ( Idle speed control valve ), this throttle air by-pass screw is sealed at the factory. and there are no provisions for curb idle adjustment. Idle air is varied by the ECU through control of the ISCV position.

22RE/3VZ-E = Adjustable Idle

2RZ-FE/3RZ-FE/5VZ-E = No Adjustable Idle

.......and just tuning the air/fuel scew on the throttle body.......
FYI. Has nothing to do with fuel.

Jay

Last edited by Jay; Dec 8, 2002 at 11:53 AM.
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Old Dec 8, 2002 | 12:00 PM
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From: SC
Thanks for the comments Jay.

Just to be sure, you don't see any negative reasons why I shouldn't lower my idle down for these winter months, right?

Thanks again-
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Old Dec 8, 2002 | 12:41 PM
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Cody, you have not seen your article yet in the round-up?
Look on the main page here.
www.yotatech.com

Scroll on down to "YotaTech on the web."

That is a "Portal" page I made to house more links so the main .com page doesn't get so cluttered.

Look for the article section near the bottom.
You can also access just about anything else that is on the forum here from that Portal page.
Corey
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Old Dec 8, 2002 | 12:50 PM
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I was wondering. Are there any negative effects to running a high idle?
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Old Dec 8, 2002 | 01:01 PM
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High idle, or a large amount of air by-passing the throttle valve can cause the infamous surging problem some are experiencing. I recommend no more than 1000 rpm at idle. Specification is likely to be at or near 800.

Jay


Note : If you notice the idle adjusting screw appears to almost fully extracted, in order to get the idle up to spec, check to see if your throttle plate needs cleaning. Some air does pass the throttle valve, and when restircted by carbon deposits, causes the need for adjusting the idle screw out.

Edit = Added Picture

Last edited by Jay; Dec 8, 2002 at 01:27 PM.
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Old Dec 8, 2002 | 01:22 PM
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From: SC
Hey Corey,

Ya I had seen it, but I just forgot how to get back to it. It looks good...thanks for doing the round-up!
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Old Dec 8, 2002 | 02:22 PM
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From: SC
Jay,

Great picture. Thanks for adding that onto this thread-
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