HPS CAI -- AFM flow table not affecting measured flow?

FlashPro questions & answers specific to the 2006-2011 Americas Civic Si
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katch22
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Joined: Wed Aug 10, 2022 6:38 pm

HPS CAI -- AFM flow table not affecting measured flow?

Post by katch22 »

Sorry for the stupidly long title, but this more or less summarizes the struggle I've been having.

Long story short: got a new HPS Cold Air Intake. I know from past experience the airflow differs greatly thank stock, and if I let the car idle for more than 20 minutes without moving, it throws a P0172 rich code. That's fine, and part of the reason why I got a Hondata Flashpro--so I could tune around this! But, for the life of me, I cannot tune around this issue. It looks like the AFM flow table doesn't affect the tune at all, even though on the basemap I am building on, AFM is selected. I am building on the AEM CAI v2 basemap.

Here's my big big problem: for the life of me, I cannot seem to change the AFM flow table to affect the fuel trims at all. I've gone through 7 maps and now the Mass flow table is about -40% lower than the base map, and yet when I look at my datalog, the mass air flow reading doesn't seem to change AT ALL.

As part of all of this, I got myself a cheapo duralast sensor just to see if the MAF was giving me a problem that I couldn't tune around. The Duralast has absolutely garbage throttle response (I keep stalling it and its hard to start from hills), but amazingly, it seems to have the correct voltage-airflow response. I know roughly what the airflow should be given a particular voltage to give roughly appropriate long term fuel trims.

Attached are datalogs and tunes, one using the duralast sensor, the other using the OEM Denso sensor.

Any tips would be appreciated. I'm pulling my hair out about this--like I said, it almost seems like any change I make to the AFM flow table has absolutely zero effect on the overall mass airflow reading.
Attachments
aemcai.newdensomaf.tune.6.1.fpdl
Low AFM flow tune, OEM Denso MAF
(5.01 MiB) Downloaded 58 times
aemcai.duralastmaf.1.fpdl
AEM CAI tune, no rev hang, cheapo Duralast MAF
(3.68 MiB) Downloaded 56 times
fa5-aem-cai-norevhang.duralast.fpcal
Tune used with Duralast datalog
(22.23 KiB) Downloaded 58 times
fa5-aem-cai-norevhang.denso.v6.fpcal
Tune used with OEM Denso datalog
(22.2 KiB) Downloaded 58 times
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Spunkster
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by Spunkster »

Have you read the info in the help file: https://www.hondata.com/help/flashpro/t ... m_flow.htm
katch22
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Joined: Wed Aug 10, 2022 6:38 pm

Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by katch22 »

Spunkster wrote: Thu Aug 18, 2022 9:11 am Have you read the info in the help file: https://www.hondata.com/help/flashpro/t ... m_flow.htm
I have and I've been following those instructions. My SFTF are between -8% and -15% from 1.1V to 3.2V, and twice I've reduced the flow rate on the AFM table by 15% and seen no change in the g/s that comes through on the datalog. I'm a bit lost as to what is up.

Attached are three XY plots: Duralast MAF, Denso MAF with no AFM flow table change (v1), and Denso MAF with AFM flow table change -30% across 0.6v to 4v (v6). There is no difference in the two Denso sensor readings and I am absolutely lost.

Duralast MAF, AFM.v x STFT
AFM.v x STFT, Duralast MAF
AFM.v x STFT, Duralast MAF
afm-stft.aem-cai-duralastmaf.v1.png (601.38 KiB) Viewed 1194 times
OEM Denso MAF, AFM.v x STFT
AFM.v x STFT, Denso MAF, default AFM Flow table
AFM.v x STFT, Denso MAF, default AFM Flow table
afm-stft.aem-cai-densomaf.v1.png (126.31 KiB) Viewed 1194 times
OEM Denso MAF, AFM flow table -30%, AFM.v x STFT
AFM.v x STFT, Denso MAF, -30% AFM flow table
AFM.v x STFT, Denso MAF, -30% AFM flow table
afm-stft.aem-cai-densomaf.v6.png (584.51 KiB) Viewed 1194 times
Hope this illustrates the fact that changing the AFM table seems to have zero effect on the actual fuel trims.
katch22
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Joined: Wed Aug 10, 2022 6:38 pm

Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by katch22 »

One more thing--here's an example of the AFM flow table making zero difference. I made huge changes to the AFM flow table between v1 and v6 and at idle, there's no tangible difference in the voltage-to-flow rate and it should be *way* less.

I do have the "rev hang eliminate" option set--does this do something behind-the-scenes like only rely on a MAP tune? If so it should be documented.

Idle, Denso MAF, no change to the AFM table
idle graph, base AFM flow table
idle graph, base AFM flow table
densomaf-idlegraph.v1.png (154.08 KiB) Viewed 1183 times
AFM flow table
base AFM flow
base AFM flow
densomaf-afmtable.v1.png (24.66 KiB) Viewed 1183 times
Idle, Denso MAF, way leaner AFM flow table
idle graph, lean AFM flow table
idle graph, lean AFM flow table
densomaf-idlegraph.v6.png (794.28 KiB) Viewed 1183 times
AFM flow table for attempt to make it leaner
AFM flow table where I tried pulling the g/s way back
AFM flow table where I tried pulling the g/s way back
densomaf-afmtable.v6.png (27.52 KiB) Viewed 1183 times
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Spunkster
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by Spunkster »

The problem may be with the intake and how the air flows through it. If you put the stock intake back on, does it work as it should?
katch22
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by katch22 »

Spunkster wrote: Thu Aug 18, 2022 1:19 pm The problem may be with the intake and how the air flows through it. If you put the stock intake back on, does it work as it should?
I haven't yet, mostly because of how much of a pain it is.

What I don't understand is how I can't tune around this? Again, if you compare the sensors, you can see that somehow the Duralast has a range of airflow to voltage response that the engine likes, but the Denso doesn't.

The fundamental question I have is: when I go to update the airflow table, it *doesn't change a single thing* as far as I can tell. I do not get why that is the case? If this table doesn't define the voltage to g/s airflow lookup, what does it do? If I get zero change when I update the table, the official documentation about tuning AFM must not be correct for this motor. Please advise?
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Spunkster
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by Spunkster »

I can assure you that this does work and many many people have tuned using this and have not had any issues. You need to try with the stock intake.
katch22
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by katch22 »

Spunkster wrote: Thu Aug 18, 2022 1:33 pm I can assure you that this does work and many many people have tuned using this and have not had any issues. You need to try with the stock intake.
And I totally believe that it must work, because it's there and in the documentation. But what I am lost about is when I change the table values, it doesn't seem to affect the ECU at all, as per the datalogs.

I totally get it if the intake is causing problems with how the sensor reads--but the problem is, when I update the table, I do not see the updated AFM table values in the datalogs. I'm just lost as to why that might be the case, or why the intake would affect the table.
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Spunkster
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by Spunkster »

Are you uploading to the ECU after making changes?
katch22
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Joined: Wed Aug 10, 2022 6:38 pm

Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by katch22 »

Spunkster wrote: Thu Aug 18, 2022 1:59 pm Are you uploading to the ECU after making changes?
I am certain I do. My workflow is:
* make changes to the calibration
* save it to a unique file so I can track changes
* upload it to the Hondata Flashpro module
* disconnect it from my PC
* hook up the flashpro to the ODBII port and follow the flash procedure

So I believe I am making changes correctly and uploading them to the ECU. I guess this is evidence that my changes are not getting up there, somehow. Can I verify in realtime what the table is if I get a laptop hooked up?
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Spunkster
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Re: HPS CAI -- AFM flow table not affecting measured flow?

Post by Spunkster »

You need to first try the stock intake and see how that works.
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