AFR peak at 4900 RPM

FlashPro questions & answers specific to the 2006-2009 (US, UK, Asia) S2000
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krando
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AFR peak at 4900 RPM

Post by krando » Sun Jun 17, 2018 1:29 pm

Hi,
I am uploading my calibration and datalog. There is an AFR peak at 4.900 Rpm that I can not understand.
No matter what I did, I could not make that spot of the AFR line flat.
At 4.900 rpm; on the sensors window INJ value goes down opposed to Fuel Low map.
It is like the Ecu is using another value on another cell for an instant.
Attachments
fz_s2000_239whp_v10.fpcal
(8.93 KiB) Downloaded 54 times
datalog1.fpdl
(77.67 KiB) Downloaded 61 times

krando
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Re: AFR peak at 4900 RPM

Post by krando » Tue Jun 19, 2018 1:40 pm

By the way the AFR peak that I am talking about is at 0:22.
What I am trying to understand is that there is a software bug or something.
Thanks

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Spunkster
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Re: AFR peak at 4900 RPM

Post by Spunkster » Tue Jun 19, 2018 5:56 pm

Look at the 4200 row and you will see that the fuel values it is reading from right before this occurs is lower then the one before and after it and this is probably the cause.

krando
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Re: AFR peak at 4900 RPM

Post by krando » Sat Jun 30, 2018 2:14 am

Hi
I have corrected row 4300 as you have stated. AFR around 4.300 got richer but the AFR peak (lean) at 4.900 rpm (WOT) still exists.
You may check the attached files.
Are you sure that this is not related to a software issue.
Attachments
fz_s2000_239whp_v13-180630-081953.fpdl
(39.76 KiB) Downloaded 48 times
fz_s2000_239whp_v13.fpcal
(8.93 KiB) Downloaded 44 times

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Spunkster
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Re: AFR peak at 4900 RPM

Post by Spunkster » Mon Jul 02, 2018 9:38 am

Are you using a dyno?

krando
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Re: AFR peak at 4900 RPM

Post by krando » Mon Jul 02, 2018 9:51 am

No,
This is happening on highway.
All the logs on this topic were taken on highway

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Re: AFR peak at 4900 RPM

Post by Spunkster » Mon Jul 02, 2018 10:20 am

You need to look at this on the dyno to see what the torque is doing when this happens, as this could be a torque peak and needs extra fuel in that spot.

krando
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Re: AFR peak at 4900 RPM

Post by krando » Mon Jul 02, 2018 11:10 am

Hi,
On the sensors tab the injector ms value decrease at that point(490 rpm). Does your torque peak theory explain this?

If you graph knock retard vs rpm you will see that at the same rpm(4900) graph starts to show knock retard.(I dont know if they are corraleted)

If you are %100 sure that the fuel low table works correctly. I will not bother you with further questions. Unfortunately I dont have access to a dyno for the moment.

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Re: AFR peak at 4900 RPM

Post by krando » Fri Jul 06, 2018 6:05 am

Any update on the subject?

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Re: AFR peak at 4900 RPM

Post by Spunkster » Fri Jul 06, 2018 9:55 am

Unfortunately I do not have any further information.

shind3
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Re: AFR peak at 4900 RPM

Post by shind3 » Fri Jul 06, 2018 9:43 pm

I'm looking at 2:18 in your v13 datalog and I see the issue you're talking about at 4900RPM.

All modern ECUs will reduce injector pulsewidth to account for the Evaporative Emissions Charcoal Canister Purge Valve activating. So in anticipation of additional fuel vapor, the ECU will reduce IPW to try to keep output AFR the same. I'm not saying that's what's happening here but it's possible the ECU is overestimating the amount of fuel vapor being released to the Intake Manifold during a 'purge' condition. I don't know if you could try a run with the Evap System disabled and see if anything changes. You might have to drive the car with the fuel cap loose so as not to overpressurize the tank. And depending on what exactly 'Purge/Evap Disabled' means for Hondata, it may or may not totally disable the logic that purges the charcoal canister. Not sure if they just disable the CEL that could arise from disconnecting the purge solenoid, tank pressure sensor, OR they actually modify the code to never activate the entire purge logic in the ECU code. For the BMW E36 ECU that I have disassembled, I can do either and given the option to the user to do either.

Besides that, the other option (I can think of) would be to see if there are underlying code changes between the US and Euro ECUs. There are quite a few parameter changes but not sure if the underlying code/logic as well as undefined paramters are the same. You could load up a US stock file and copy over all the tables that are 'different' by using the File -> Compare option.

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