WTH? Idle Speed Timeout IAC Steps vs Coolant Temp??
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
WTH? Idle Speed Timeout IAC Steps vs Coolant Temp??
Title pretty much says it all, what the crap does the Idle Speed Timeout IAC Steps vs Coolant Temp table do?
My car is a 92 LT1. C'mon Alvin, whatcha know about it?
Thanks.
My car is a 92 LT1. C'mon Alvin, whatcha know about it?
Thanks.
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
Never had to touch that table for anything..
Anyway, don't trust anything that anyone says.. make a change to the table and see how it reacts in the car. Since there is no authority on this subject it is best to figure this stuff out on your own instead of relying on what others tell you what this table should do. I find the people that rely on other people to find "what should I change my pe tables to" always end up in a pickle later on.
Anyway, don't trust anything that anyone says.. make a change to the table and see how it reacts in the car. Since there is no authority on this subject it is best to figure this stuff out on your own instead of relying on what others tell you what this table should do. I find the people that rely on other people to find "what should I change my pe tables to" always end up in a pickle later on.
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Yeah, I understand that completely. I was just curious if anybody knew exactly what it was supposed to do before I started messing with it. I like to have a LITTLE knowledge before I go tinkering around. Notice I didn't ask what it should be set to, just curious what it does. Having some idea what it effects before you change it might help you notice the changes. Sometimes it can be very subtle and you have to pay attention VERY carefully to pick up on a small change.
Le Mans Master
Joined: Mar 2002
Posts: 5,889
Likes: 2
From: Castro Valley Calif.
St. Jude Donor '03 thru '26
Nathan, I am really ignorant about this stuff, but here's a link to an in depth discussion on the IAC from my "trying to learn" collection. I don't know if this has what you're looking for, but it's interesting reading nonetheless
http://www.diy-efi.org/gmecm/papers/747iac.txt
http://www.diy-efi.org/gmecm/papers/747iac.txt
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
Originally Posted by Nathan Plemons
Title pretty much says it all, what the crap does the Idle Speed Timeout IAC Steps vs Coolant Temp table do?
My car is a 92 LT1. C'mon Alvin, whatcha know about it?
Thanks.
My car is a 92 LT1. C'mon Alvin, whatcha know about it?
Thanks.
I have both P507 & P1509 codes......trying to understand if my IAC died or is intermittant or what......sympton is high idle..1500rpm...
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
I don't know if it will or not. I know datamaster will, or at least I believe it probably shows the COMMANDED IAC position, I don't know if it will report the actual IAC position.
If you want to know if your IAC is bad, unplug it while the car is idling. It should die, if it doesn't the IAC is likely stuck. At least that's how it works on Fords.
If you want to know if your IAC is bad, unplug it while the car is idling. It should die, if it doesn't the IAC is likely stuck. At least that's how it works on Fords.
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Originally Posted by Nathan Plemons
If you want to know if your IAC is bad, unplug it while the car is idling. It should die, if it doesn't the IAC is likely stuck. At least that's how it works on Fords.
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Melting Slicks
Joined: Jun 1999
Posts: 2,949
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From: Bowling Green KY
Nathan, I was curious if Tunercat had updated help files. The answer was no but while I had their attention I asked about this table, this was the response:
"The IAC Park Position Vs. Coolant Temp table specifies the IAC motor
position that is commanded by the ECM immediately after engine startup. After a short delay the ECM then begins controlling the idle RPM by adjusting the IAC position"
"The IAC Park Position Vs. Coolant Temp table specifies the IAC motor
position that is commanded by the ECM immediately after engine startup. After a short delay the ECM then begins controlling the idle RPM by adjusting the IAC position"
