minimum idle
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
It's not bad.
Some of the diagnostic tests call for running the motor with the jumper in place to observe the car going into closed loop. I think the flashing slows down when it reaches closed loop.
Some of the diagnostic tests call for running the motor with the jumper in place to observe the car going into closed loop. I think the flashing slows down when it reaches closed loop.
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by CFI-EFI
I agree, but...see post #12. Colder engines need a faster idle and a richer mixture than a warm engine. The ultra slow minimum air idle speed will be more stable in a warm engine and with a mixture suited to that warmer temperature.
RACE ON!!!
RACE ON!!!
Originally Posted by ozvette87
most things i read with instructions on linking a' b' terminals on the aldl say Not to start the engine. i have personally seen it started with the terminals linked and all that seems to happen is the ses flashes really fast.
why is it so bad to start the car with the two terminals linked?
why is it so bad to start the car with the two terminals linked?
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Originally Posted by Casethecorvetteman
How so? The computer aims for a certain RPM and sets the IAC for that, not aims for a certain IAC position. It made no difference for me(ever).......So i really don't see how doing it hot or cold can make the idle speed setting in the computer change
However, with the motor being *cold (see below) it may require the T. blade to be opened more to sustain, or to idle @450, as opposed to a motor already being warmed up at least. Then with the IAC plugged in, and under ECM control, because the min. air screw being turned in possibly too much to compensate the cold motor, it would then be possible to be out of range for the ECM to adjust.
The IAC does have a decent amount of "range" that it can compensate when under computer control and really only needs to get close. Obviously this would all then depend on: how cold is cold, and how much someone was twisting the screw to get it to idle @450rpm. I guess cold is relevant to where you live and a given day.
My Idea of a *cold setting, would be trying to set the min. air when the coolant/ambient temps. would be 50ish. Fahrenheit. Personally I have never tried to set set it up cold. I do it so I know where the counts are at O.T. If you are getting good results doing it that way, the result is all that matters.
Last edited by mseven; Aug 4, 2006 at 10:20 AM.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by ozvette87
most things i read with instructions on linking a' b' terminals on the aldl say Not to start the engine. i have personally seen it started with the terminals linked and all that seems to happen is the ses flashes really fast.
why is it so bad to start the car with the two terminals linked?
why is it so bad to start the car with the two terminals linked?
RACE ON!!!
Cruising
Joined: Jul 2006
Posts: 14
Likes: 0
Ive just tried to reset the idle on my 1987 after fitting a new IAC valve. I followed the procedure as above, and when i connected things back up, the car was idling at 1400 rpm! So i just turned the screw down again, which defies the point of resetting it to the book really. Should i have left it at 1400 rpm and taken it for a drive to let it "settle"?
Le Mans Master
Joined: May 2005
Posts: 5,214
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From: Queensland, AUSTRALIA
Originally Posted by mseven
My Idea of a *cold setting, would be trying to set the min. air when the coolant/ambient temps. would be 50ish. Fahrenheit. Personally I have never tried to set set it up cold. I do it so I know where the counts are at O.T. If you are getting good results doing it that way, the result is all that matters.
Originally Posted by cymro
Ive just tried to reset the idle on my 1987 after fitting a new IAC valve. I followed the procedure as above, and when i connected things back up, the car was idling at 1400 rpm! So i just turned the screw down again, which defies the point of resetting it to the book really. Should i have left it at 1400 rpm and taken it for a drive to let it "settle"?
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by cymro
Ive just tried to reset the idle on my 1987 after fitting a new IAC valve. I followed the procedure as above, and when i connected things back up, the car was idling at 1400 rpm! So i just turned the screw down again, which defies the point of resetting it to the book really. Should i have left it at 1400 rpm and taken it for a drive to let it "settle"?
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Le Mans Master
Joined: May 2005
Posts: 5,214
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From: Queensland, AUSTRALIA
Originally Posted by CFI-EFI
YES. Or reaclimate it as outlined in your FSM. You don't just "reset the idle". The idle speed is burned into your prom. The proceedure above is for setting the minimum air adjustment. Did "i just turned the screw down again" reduce the idle speed? It shouldn't have. Turning the screw down (in) could increase the idle speed, but not lower it.
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Race Director
Joined: Sep 2000
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From: The Top of Utah
I would have thought so too, but that isn't what he said. Besides backing off of the minimum air adjustment screw, shouldn't lower the idle speed with the IAC wide open. "You don't just "reset the idle". The idle speed is burned into your prom."
RACE ON!!!
RACE ON!!!
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Originally Posted by CFI-EFI
I would have thought so too, but that isn't what he said. Besides backing off of the minimum air adjustment screw, shouldn't lower the idle speed with the IAC wide open. "You don't just "reset the idle". The idle speed is burned into your prom."
RACE ON!!!
RACE ON!!!
, something else is not done right there.
Le Mans Master
Joined: Feb 2005
Posts: 5,146
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From: The Motor City
Originally Posted by CFI-EFI
"You don't just "reset the idle". The idle speed is burned into your prom."RACE ON!!!
Race Director
Joined: Jun 2004
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From: WI
"7. Start the engine and adjust the minimum air to the specified (desired) rpm."
550 is the right RPM? I went out and tried this on mine just now. My car idles fine, 600 RPM in drive. I turned the screw as far as it would go and it would not go under 1200 RPM. Odd.
550 is the right RPM? I went out and tried this on mine just now. My car idles fine, 600 RPM in drive. I turned the screw as far as it would go and it would not go under 1200 RPM. Odd.
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by mseven
OMG, this just makes me wonder if anyone bothers to read ALL of the posts...................
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Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Originally Posted by CFI-EFI
Me too. You DO realize what you quoted me as saying in post# 27, was in response to cymro's post# 25. You DID read ALL the posts, right?RACE ON!!!
OF Course........
Last edited by mseven; Aug 4, 2006 at 07:53 PM.
