IAC too low
05-07-2007, 11:14 AM
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IAC too low My 99z runs great but the afr at the idle rpms is very rich. I posted this on tuners but have not gotten much response
I read how to adjust the IAC but it does not do much. The following is what I read to do and what I have.......
Said to get TP Voltage between "40-60" My TP voltage 55. Thats good. Said that the IAC count is suppose to be between "60-80 non cam cars" mine is 16 when warmed up. Now I did not actually see the "IAC Count" for a selection. I did see and log the "IAC Desired Position" and "IAC Position". Both of those are 16.
The car runs/idles great, I just dont like to see a 12.11 afr at idle. I think this might have something to do with it. I do have a ported TB but did not mess with drilling that hole they said to do if your IAC is too high. How would I make this go up, fill inthe hole a little? And am I even logging the right things?
TIA
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I read how to adjust the IAC but it does not do much. The following is what I read to do and what I have.......
Said to get TP Voltage between "40-60" My TP voltage 55. Thats good. Said that the IAC count is suppose to be between "60-80 non cam cars" mine is 16 when warmed up. Now I did not actually see the "IAC Count" for a selection. I did see and log the "IAC Desired Position" and "IAC Position". Both of those are 16.
The car runs/idles great, I just dont like to see a 12.11 afr at idle. I think this might have something to do with it. I do have a ported TB but did not mess with drilling that hole they said to do if your IAC is too high. How would I make this go up, fill inthe hole a little? And am I even logging the right things?
TIA
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05-07-2007, 01:00 PM
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Fueling doesn't really have much (if anything) to do with the IAC valve. That's corrected with the MAF, VE, and commanded AFR tables. Either your car is commanding a rich condition at idle or your fueling is off.
To get the IAC steps up, you want to back out your throttle body set screw to close the blade slightly. This will make the IAC valve open more to compensate for the reduced airflow around the blade, which will read as a higher number of steps. If your set screw is backed all of the way out, then there's little you can do. If the IAC steps were too high, you would open the blade some with the set screw. You follow?
To get the IAC steps up, you want to back out your throttle body set screw to close the blade slightly. This will make the IAC valve open more to compensate for the reduced airflow around the blade, which will read as a higher number of steps. If your set screw is backed all of the way out, then there's little you can do. If the IAC steps were too high, you would open the blade some with the set screw. You follow?