High idle issues (1 Viewer)

MoGas

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I searched, I checked FAQ's, I couldn't find what I was looking for....


At any start up after it has had a chance to cool down (morning start, start at lunchtime, start after work) I get a high idle (1200rpm) right off the bat and will maintain that idle for at least a couple minutes. It does not do this unless it has sat for a few hours. Ambient air temp makes no difference. I replaced the acellerator cable a few weeks ago and it still does it. I have tried with the cables disconnected from the throttle and it still does it.

Is this normal?
If not, where do I look for a fix?



:cheers:
Dave
 
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Cold Idle Fix

The following link will take care of the problem... if you are only idling at 1200 rpms, I would only put one O ring on the shaft. Putting two might put your RPM to low. You can always add another one if need be. Its a simple installation, ACE hardware has the O rings you will need. My wifes 1993 was idling at 1700-1800 at cold idle, I dont know why Toyota ever thought that was a good idea :confused: does anyone else????

----Fman

This should get you going... good luck !

http://www.safari4x4.com.au/80scool/tech/fast_idle/fast_idle.html
 
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1200 sounds about right for start idle, ushually the o-ring fix is for idles over 2k
 
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Mine was brought down to around 900, which is perfect --- not hard on the tranny when it is cold and still moderately warms the engine up.
 

MoGas

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Fman said:
The following link will take care of the problem... if you are only idling at 1200 rpms, I would only put one O ring on the shaft. Putting two might put your RPM to low. You can always add another one if need be. Its a simple installation, ACE hardware has the O rings you will need. My wifes 1993 was idling at 1700-1800 at cold idle, I dont know why Toyota ever thought that was a good idea :confused: does anyone else????

----Fman

This should get you going... good luck !

http://www.safari4x4.com.au/80scool/tech/fast_idle/fast_idle.html


This is exactly what I was looking for. Thanks


:cheers:
Dave
 

MoGas

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RavenTai said:
1200 sounds about right for start idle, ushually the o-ring fix is for idles over 2k

It that normal for all cool starts of the day or for the cold start in the morning?


:cheers:
Dave
 
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After driving, the cooler your engine becomes the higher RPM the next rpm will be. The ECU works with a spring mechanism that reacts to the heat of the motor. Its normal in the morning to start up your rig and have it idle at the "higher" rate than when you are done driving it, run into the store and come back out and start it up. By installing the O rings you shorten the length of the spring opening which reduces the amount of air that can enter your motor and drops your RPMs down.

Make sure and put loc-tite on those three little screws once you re-install, you dont want them rattling loose and falling into your engine.... that could really ruin your day!
 
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the spring mechanisim is actually a stepper motor. the ECU learns learns how to position it for cold start over time by trial and error. if you disconect the battery it has to re learn the idle air motor.

I cannto remember what the idle is for the second start on my 80 but it never seams excessive for the situation.

whern I pull my battery I get 2K and up start up idle, it goes down every start after that until it levels out, some people report that thiers never learns and cold start idle stays very high, so they do the o-ring trick. i do not know why some learn and some do not. excessively high start up RPM is associated with start up rattle.

maybe some ECUs have a learning disability and ride on the short bus?
 

MoGas

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Does anyone know what size o-rings?

I'd rather pick some up before taking it apart.


:cheers:
Dave
 

MoJ

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MoGas said:
Does anyone know what size o-rings?

I'd rather pick some up before taking it apart.


:cheers:
Dave


--->Remove shaft by rotating motor (not seen in pic because it is behind flange). Place O ring(s) on shaft. O rings are 8mm ID x 1.5mm section (or 5/16" ID x 1/16" section). <---
 

MoGas

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MoJ said:
--->Remove shaft by rotating motor (not seen in pic because it is behind flange). Place O ring(s) on shaft. O rings are 8mm ID x 1.5mm section (or 5/16" ID x 1/16" section). <---


Yeah, I just re-read the instructions.:doh:


:cheers:
Dave
 

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