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Rb25det turn poor afr after 6500rpm

Posted: Wed Apr 25, 2018 7:15 am
by stinger
Hi,

Need help for my problem.

On full throttle, AFR run good until 6500rpm: 11,5AFR
But 6500rpm to 7400rpm, AFR go poor: 12,5AFR

My log show that injection-time decrease after 6500rpm. TP (Load) decrease too..
6500rpm to 7400rpm, MAF stay at 50268value.

If you have any ideas...

My setup:
Rb25det S2
Maf Z32
Injector deatschwerks 550cc
GT3076R 15psi

Thanks

Re: Rb25det turn poor afr after 6500rpm

Posted: Thu Apr 26, 2018 3:20 am
by iyarovoy
You need to post your tune as well (.bin file from nistune) such that we can see all your parameters at work instead of analyzing the Excel spreadsheet.

Re: Rb25det turn poor afr after 6500rpm

Posted: Thu Apr 26, 2018 3:51 am
by stinger
There is my tune.

I noticed in Throttle Enrich 1/2/3/4 all values are at 255... It is possible to create problem?
I can't test today with standard values.

Re: Rb25det turn poor afr after 6500rpm

Posted: Fri Apr 27, 2018 7:28 am
by Matt
Put the throttle enrich tables to normal. However I don't think it will be related to this issue

Below log shows the problem:
tracerb25.PNG
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You can see that RPM keeps increasing, but MAF load measured (blue) stops increasing at the same rate, and then TP calculated load (grey) and injection time (orange) start dropping off

The only way to stop it leaning out here is to add more fuel to the affected part of the fuel map, so the orange line stays up, despite TP dropping. I cannot think of any other way around this

Re: Rb25det turn poor afr after 6500rpm

Posted: Mon Apr 30, 2018 5:04 am
by stinger
Thanks for your answer Matt.
Sans titre.jpg
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It is better but it's not beautiful :?

Do you think I can edit VQ Map on the column concerned to increase the value?

Re: Rb25det turn poor afr after 6500rpm

Posted: Tue May 01, 2018 10:14 am
by Matt
Normally I see that type of map when we see fuel pump issues (fuel pressure drops) but in this case we know the MAF load is dropping

You can also increase the VQ map to push the TP higher, but it is not necessary if the above fuel map does the same job