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Author Topic: Desired boost/load oscillation after ~4300rpm  (Read 16607 times)
amd is the best
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« Reply #30 on: June 07, 2017, 08:23:31 AM »

Looks like a MAF problem to me, AFR is on the lean side and with a boost leak it would be rich. Could be because of E85 adjustments, nothing unexpected. Also the difference between actual and req looks to be only <100mbar in the maf unhooked log. You have a known well working maf around? Boost leak test is always good, but I am not convinced that is the problem.

I actually can get a hold of the MAF my file originally calls for. I'll swap that in as well as check for leaks and report back.
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nyet
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« Reply #31 on: June 07, 2017, 11:06:59 AM »

Looks like a MAF problem to me, AFR is on the lean side and with a boost leak it would be rich. Could be because of E85 adjustments, nothing unexpected. Also the difference between actual and req looks to be only <100mbar in the maf unhooked log. You have a known well working maf around? Boost leak test is always good, but I am not convinced that is the problem.

Maybe i have this backwards, but it looks like it is struggling to pull fuel here

0.82 lamba control is no joke.. as is 100mbar at only 600mbar of boost.

And if the problem is "MAF too high" it would ALSO be rich.

« Last Edit: June 07, 2017, 11:09:12 AM by nyet » Logged

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TijnCU
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« Reply #32 on: June 07, 2017, 11:38:48 AM »

I only looked at the maf disconnected log, because the faulty maf values skew everything. For sure it is logical the ecu has to pull fuel if it thinks its getting 150gs of air when it is actually 100. But on the disconnected log you see it is actually running lean (1.1-1.25 correction). In my opinion that is not a logical side effect of a boost leak, ecu should expect a very minimal amount of air and in this scenario (if fueling was sorted) the car should produce more intake than calculated, ergo not possible that air is leaking away. But I think this fuel trim had to do with e85 calibrations in this case.
« Last Edit: June 07, 2017, 11:40:40 AM by TijnCU » Logged

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« Reply #33 on: June 07, 2017, 11:46:25 AM »

I only looked at the maf disconnected log, because the faulty maf values skew everything. For sure it is logical the ecu has to pull fuel if it thinks its getting 150gs of air when it is actually 100. But on the disconnected log you see it is actually running lean (1.1-1.25 correction). In my opinion that is not a logical side effect of a boost leak, ecu should expect a very minimal amount of air and in this scenario (if fueling was sorted) the car should produce more intake than calculated, ergo not possible that air is leaking away. But I think this fuel trim had to do with e85 calibrations in this case.

Makes sense to me.
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ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
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