Cold start iac counts question
Thread Starter
On The Tree
Joined: Jun 2015
Posts: 113
Likes: 12
From: Hopewell Junction NY
Cold start iac counts question Hello guys just trying to dial in my idle via hp tuners. I bought a new iac motor and trying to dial it in. Weird thing is the iac counts start off high 270 then eventually come down to only 150 on a warmed up engine. Which I know is way too high. If I shut the car off, restart it the counts will start like 190 and quickly come down to the 75-80
range where I set it at. Could it be a reset situation or a iac steps vs effective area in tune issue? I’m puzzled . I shouldn’t have to restart the car for iac to act normally on warmed up engine . Any solutions or things to try would be appreciated!
range where I set it at. Could it be a reset situation or a iac steps vs effective area in tune issue? I’m puzzled . I shouldn’t have to restart the car for iac to act normally on warmed up engine . Any solutions or things to try would be appreciated!
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From: Ann Arbor, MI
Please tell us exactly which engine, throttle body and PCM/ECU you have, and if possible the part number for the new IAC motor.
You likely had no replies after 75 views because there just wasn't enough information.
Knowing the IAC part number, someone might have working "iac steps vs effective area" values, which are not easy to calculate. (Well, at least not for me.)
You likely had no replies after 75 views because there just wasn't enough information.
Knowing the IAC part number, someone might have working "iac steps vs effective area" values, which are not easy to calculate. (Well, at least not for me.)
This was the IAC tuning information provided to me from Pat G on both of my cars. .
Hope this helps!
To set the proper IAC idle airflow with the throttle blade. Monitor IAC position on your VCM scanner with the config file I've supplied. Let the engine warm up and observe the IAC counts. Ideally, they need to be between 30-60 at warm idle with the ac off. If the counts are higher than this, you need to open up the throttle blade more with the set screw or you need to drill a larger hole in the TB blade. Regardless of which approach you choose, you will need to get the IAC counts in this range to have good idle recovery. If the counts are lower than 30, you are letting in too much air and you'll need to close the TB blade some. Make sure you shut down the car and start a new log after a throttle adjustment so the TPS sensor will re-index itself.
I will also note that I have Nick Williams throttle bodies on both of my cars the 01 has a 102mm and the 99 has the 92mm and I did not have to drill a hole in my 102 or open up the one on the 92 in order to get the idle counts into the specified range.
Hope this helps!
To set the proper IAC idle airflow with the throttle blade. Monitor IAC position on your VCM scanner with the config file I've supplied. Let the engine warm up and observe the IAC counts. Ideally, they need to be between 30-60 at warm idle with the ac off. If the counts are higher than this, you need to open up the throttle blade more with the set screw or you need to drill a larger hole in the TB blade. Regardless of which approach you choose, you will need to get the IAC counts in this range to have good idle recovery. If the counts are lower than 30, you are letting in too much air and you'll need to close the TB blade some. Make sure you shut down the car and start a new log after a throttle adjustment so the TPS sensor will re-index itself.
I will also note that I have Nick Williams throttle bodies on both of my cars the 01 has a 102mm and the 99 has the 92mm and I did not have to drill a hole in my 102 or open up the one on the 92 in order to get the idle counts into the specified range.
Thread Starter
On The Tree
Joined: Jun 2015
Posts: 113
Likes: 12
From: Hopewell Junction NY
Please tell us exactly which engine, throttle body and PCM/ECU you have, and if possible the part number for the new IAC motor.
You likely had no replies after 75 views because there just wasn't enough information.
Knowing the IAC part number, someone might have working "iac steps vs effective area" values, which are not easy to calculate. (Well, at least not for me.)
You likely had no replies after 75 views because there just wasn't enough information.
Knowing the IAC part number, someone might have working "iac steps vs effective area" values, which are not easy to calculate. (Well, at least not for me.)
hey thanks for the message. The car is a cammed ls1 fast 92 nw 92mm tb . So it’s a rock auto stock replacement pn# is ultra power AC162. So I went through the iac vs effective table histogram from one of the members here chopper doc . I dialed that in STIT and dynamic air vs desired air was spot on. Iac counts 70-80 on fully warmed up engine. However the car would not recover on a throttle blip and would always undershoot. So for test purposes I threw in this cheap rock auto iac motor and set my iac steps vs effective area back to stock for 2002 camaro ls1 from 0-100 I then interpolated 100-200 in the table and loaded it up. It’s hangs a little but is not stalling and undershooting like before . I know it’s not proper practice but I had no other success with iac tuning . If you have any insight on how to properly do this I’m all ears .. thanks
Thread Starter
On The Tree
Joined: Jun 2015
Posts: 113
Likes: 12
From: Hopewell Junction NY
This was the IAC tuning information provided to me from Pat G on both of my cars. .
Hope this helps!
To set the proper IAC idle airflow with the throttle blade. Monitor IAC position on your VCM scanner with the config file I've supplied. Let the engine warm up and observe the IAC counts. Ideally, they need to be between 30-60 at warm idle with the ac off. If the counts are higher than this, you need to open up the throttle blade more with the set screw or you need to drill a larger hole in the TB blade. Regardless of which approach you choose, you will need to get the IAC counts in this range to have good idle recovery. If the counts are lower than 30, you are letting in too much air and you'll need to close the TB blade some. Make sure you shut down the car and start a new log after a throttle adjustment so the TPS sensor will re-index itself.
I will also note that I have Nick Williams throttle bodies on both of my cars the 01 has a 102mm and the 99 has the 92mm and I did not have to drill a hole in my 102 or open up the one on the 92 in order to get the idle counts into the specified range.
Hope this helps!
To set the proper IAC idle airflow with the throttle blade. Monitor IAC position on your VCM scanner with the config file I've supplied. Let the engine warm up and observe the IAC counts. Ideally, they need to be between 30-60 at warm idle with the ac off. If the counts are higher than this, you need to open up the throttle blade more with the set screw or you need to drill a larger hole in the TB blade. Regardless of which approach you choose, you will need to get the IAC counts in this range to have good idle recovery. If the counts are lower than 30, you are letting in too much air and you'll need to close the TB blade some. Make sure you shut down the car and start a new log after a throttle adjustment so the TPS sensor will re-index itself.
I will also note that I have Nick Williams throttle bodies on both of my cars the 01 has a 102mm and the 99 has the 92mm and I did not have to drill a hole in my 102 or open up the one on the 92 in order to get the idle counts into the specified range.
Hey thanks . I actually got this same message from
Pat G when he did a mail order tune for me. I’ve since taken this tuning thing upon myself because I’m a firm believer in if you want something done right you have to learn and do it yourself . Tuning requires a lot of patience and time to dial it in just right .Thats hard to do with a mail order tune. Hopefully the end result I will have learned something and the car will be hopefully faster with the right tweaks.