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IAT compensation

Posted: Sun Aug 07, 2016 10:09 pm
by Yungone501
Was trying to narrow down an issue I've been having with low load knock and noticed something unusual so I assumed it best to ask instead of not knowing. The questions is, does the "air temperature fuel compensation cranking" table ONLY apply to cranking events or does it affect AFR's after cranking as well (i.e. All areas of the MAP in fuel tables)? The only reason I ask is because I can see a tracer highlighting the table when IAT changes occur throughout a datalog and got me wondering. If it only influences cranking trim, is there any other table that can be used to help me correctly correct the drastic AFR swings I'm seeing day to day from ambient temperature changes. My AFR's can easily swing a solid point or less when temps fluctuate anywhere from 15-20F.

Thanks,

Robert.

Re: IAT compensation

Posted: Sun Aug 14, 2016 7:49 am
by Hondata
Only used when cranking. All tables are traced all the time.

Re: IAT compensation

Posted: Mon Aug 22, 2016 7:24 pm
by Yungone501
I'm assuming since the remaining question was disregarded, that translates to a "no"?

I am really struggling with this issue especially now that fall is beginning to show its face.

Re: IAT compensation

Posted: Tue Aug 23, 2016 9:13 am
by Hondata
fgrep -o ? <post> | wc -l = 1, so all questions answered.

Please post more information, including calibration & datalogs showing. I'd check injector dead times and if the IAT is metering the air temperature (stock intake tube or aftermarket?)

Re: IAT compensation

Posted: Thu Nov 24, 2016 1:31 am
by Yungone501
Let me first explain some new issues I'm having here lately and hopefully you can lead me in the right direction.

I've switched from running pump gas to e85 and in the warmer months I had very little fluctuations in my AFRs but now that the cooler months are approaching, I've began to have some even greater inconsistencies with them lately. I've since realized that having a low temp stat has caused some insanity in the tune as now I have the ECT fuel compensation tables that are also working against me but I've just started to clear this up by re-indexing the temps and what they're supposed to be adding. I'm assuming that this table will also be greatly affected by the lack of not having an IAT fuel compensation table in FlashPro and need to know if I'm working against the tune. I've seen you mention that the IAT fuel comps are not currently available in another thread (not sure why this is) but it's becoming very apparent it seems that I'll probably need to rid my car of the stock ECM and go with a standalone but wanted to know your take on this? Should I keep at the adjustments here or do you think the stock ECMs inability to configure IAT fuel comp will ever allow me a tune that will require MINIMAL ADJUSTMENTS BETWEEN SEASONS (this is my ultimate goal)?

PS- Even before I went with the low temp stat, my AFRs would still fluctuate by a great deal between seasons.

Thanks.