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Base Idle help plz?

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Old 05-18-2009, 05:51 PM
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Ze2222
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Default Base Idle help plz?

Hi guys i was in the garage trying to reset my idle because it sits around 1000 to 1200 all the time.

I disconnected the iac and adjusted the throttle screw, well with it backed off all the way without even hitting my vehicle runs at 950 to 1000. I cut the engine and disconnected battery, sat for 10-15 mins then restarted it up"still with iac disconneced" it idles at 950 to 1000, i tried pushing the throttle closed more but wouldn't go down, i then noticed my throttle was sticky, so i remove throttle body and cleaned it up, reinstall it and still same thing.
From reading up on the base idle reset i'm under the assumption that i could go as low as 750? why can't i get the idle to go down lower, Should i try new throttle body? Any help would be appreciated thx.
Sry car is a 1990 stang 5.L "stock"
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Old 05-18-2009, 06:39 PM
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87foxgt
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readjust the screw, that's why your throttle is sticking... 950 - 1000 is normal and is what my car runs at...
if it runs high with the IAC valve plugged in, clean it or buy a new one...

How to reset idle -> http://www.muscularmustangs.com/idlereset.php
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Old 05-18-2009, 06:54 PM
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Ze2222
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thx for the help, k well lemme see if i have this correct. With my stop screw not hitting the throttle bracket it idles at 1000, but if i bring the stop screw up to it, it moves it past 1000, and then with iac goes to 1200. I'll try new iac.

I have read other base idle adjustment procedures and alot of them say disconnect and start, says engine might start then die. Mine doesn't at all, even with screw far off doesn't that seem odd? Sry i'm new to this and learning excuse the learning curve.
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Old 05-18-2009, 07:55 PM
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Ze2222
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k upon reading several articles. People are setting there base idle to 750 to 850. Is that correct? if so why can't i get mine that low? even with the throttle screw out? anyone?
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Old 05-18-2009, 08:20 PM
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camaroeater
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i would check ALL vacuum lines for leaks, clean the iac, and make sure the the throttle cable move easily by opening it by hand. If its sticking, spray it with some lubricant.
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Old 05-18-2009, 08:35 PM
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86 5.0L
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Originally Posted by 87foxgt
950 - 1000 is normal and is what my car runs at...
not true...
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Old 05-18-2009, 08:57 PM
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87foxgt
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I was told under a 1000 is normal...
but if you know something I don't please share instead of just saying not true... We must work as a team, and if I just called timeout when we don't have any(FAB-5 Chris Webber) let me know... So what do you call normal then?
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Old 05-18-2009, 09:17 PM
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86 5.0L
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600 for manual
750 for auto
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Old 05-18-2009, 09:33 PM
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Joel5.0
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Looks like you could have a faulty IAC valve. Remove valve, get a rag so you don't burn your fingers, have someone start the engine while you become the IAC valve by partially blocking the IAC transfer holes with your fingers. If you block it and idle drops below 600 rpm or engine stalls....... replace the IAC valve.
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Old 05-20-2009, 07:03 PM
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Ze2222
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k well i tried like u said joel and did as instructed engine would start then die right away which is a good thing, so i went and purchased another iac valve. Installed it.
Started vehicle up and again idles at 1000 rpm with throttle stop screw backed all the way off. Iac valve still unplugged. Why can't i get the idle to go lower? Faulty throttle body? I inspected it, it doesn't stick. when i had it remove the first time there was ridges in there that i had to sand down so it could close and open smoothly. Any thoughts or inputs are welcome.
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