Hesitation Issues 3000-4500rpm - BM3 Log

[TSHRTS_M4]

Can anyone give me some insight on this log. 2016 M4 - Having a hesitation between 3000-4500 when pushing gas full throttle. If I ease the gas and do not floor it, it pulls just fine to redline. Only does this on hard acceleration and in ANY mode (sport, sport+) etc. Stage 2 91-93 OTS map

https://www.bootmod3.net/log?id=6193...pUG6DHsHqBo6iA

Thanks so much!

[Weytens]

I'm not an expert, but on this log i never see full throttle.

[TSHRTS_M4]

Well maybe not that log showing full throttle but definitely hesitation on that log under heavy acceleration and then I backed off soon as it hesitated ...

[Donteflon]

Originally Posted by TSHRTS_M4

Can anyone give me some insight on this log. 2016 M4 - Having a hesitation between 3000-4500 when pushing gas full throttle. If I ease the gas and do not floor it, it pulls just fine to redline. Only does this on hard acceleration and in ANY mode (sport, sport+) etc. Stage 2 91-93 OTS map

https://www.bootmod3.net/log?id=6193...pUG6DHsHqBo6iA

Thanks so much!

You have a very brief period of WOT angle. With the minimum data given, I looked at corrections (which were minimal and cleaned up), fuel pressure (which met target and held), boost target, pre-throttle as well as deviation (.2 delta/non significant imo), and last WGDC.

The only thing that stood out as odd to me was during that brief period of WOT, your WGDC had small oscillation (looks like waves on the graph).

From experience, this can lead to choppy boost and make the car feel like its surging/hesitating. Is this what you are describing/experiencing?

Is this car stock? OTS tuned? <-- EDIT: I see that its on an OTS map.

This can very likely be tune related. Boost oscillation as well as finnicky wastegates can be smoothed out by the tuner. If software changes don't help, then you can start looking mechanically.

[TSHRTS_M4]

Originally Posted by Donteflon

You have a very brief period of WOT angle. With the minimum data given, I looked at corrections (which were minimal and cleaned up), fuel pressure (which met target and held), boost target, pre-throttle as well as deviation (.2 delta/non significant imo), and last WGDC.

The only thing that stood out as odd to me was during that brief period of WOT, your WGDC had small oscillation (looks like waves on the graph).

From experience, this can lead to choppy boost and make the car feel like its surging/hesitating. Is this what you are describing/experiencing?

Is this car stock? OTS tuned?

Yes!! That's exactly what I'm experiencing! Choppy hesitation .. If I keep accelerating, once I hit about 5000 rpm it never happens again .. Only within those 3000-4500rmp does it do this. I can ease the acceleration and it will pull no problem with none of the hesitation, only when I give it heavy throttle it does this … Car is on the OTS Multimap Stage 2 ACN tune .. I'm in Arizona … Car has AA catless downpipes, AA Single Midpipe and Agency Power Front Mounted Intakes

[heitzke]

I've never logged anything part-throttle so I'm really unsure and don't have a good baseline to compare it against but interestingly your bank 1 AFR shoots up suuuper lean after the 4500 mark vs bank 2 that sticks with the lambda target. Also during this time is when your STFT also split apart and the bank 1 STFT value is lower than bank 2.

When I had a brief moment of this in the tuning process with F80Paul he suggested possible a stuck/leaky injector, but also that resetting the 'learned adaptations' underneath the diagnostics tab was also a good thing to do after changing maps.

[Donteflon]

Originally Posted by heitzke

I've never logged anything part-throttle so I'm really unsure and don't have a good baseline to compare it against but interestingly your bank 1 AFR shoots up suuuper lean after the 4500 mark vs bank 2 that sticks with the lambda target. Also during this time is when your STFT also split apart and the bank 1 STFT value is lower than bank 2.

When I had a brief moment of this in the tuning process with F80Paul he suggested possible a stuck/leaky injector, but also that resetting the 'learned adaptations' underneath the diagnostics tab was also a good thing to do after changing maps.

This is a solid point too. I totally neglected the AFRs and the possibility of injectors being an issue. Part of me feels doubtful about it though. He's not running ethanol and his HPFP actual is 2800 psi. That's a very healthy pressure and I doubt it's stressing the injectors out. But iunno. It's hard to deduce from this log, but then again, I am not a tuner myself, and am self taught in regard to log interpretation as well as having my own anecdotal experiences.

Nonetheless, good point, heitzke

I'll also have to walk back what I said about the oscillation since that happens after 3k-4.5k as well as the touch & go accelerator/throttle input after the initial pull contributing to what I thought was oscillation. WGDC looks okay and boost is smooth in the 3k-4.5k range.

[TSHRTS_M4]

Man, thank you guys for this input so far!! I may have another log, I will see and post if I do. I haven't ran the car for a week.

So as I am taking this I need to "reset adaptations" FIRST and see if that helps? If not should I start looking into a custom tune and getting the injectors looked at?

[TSHRTS_M4]

Here is another Log ... This one may be better

https://www.bootmod3.net/log?id=6193...0b4340b876bd26

[Donteflon]

Originally Posted by TSHRTS_M4

Here is another Log ... This one may be better

https://www.bootmod3.net/log?id=6193...0b4340b876bd26

Bank 1 STFT is lean while Bank 2 STFT is right on the money with a great lambda. This supports what heitzke was saying earlier.

Additionally, you're getting timing retardation in Cyls 1-2 which is Bank 1, the same bank where your trims are lean.

I don't think this is a coincidence and there is a correlation.

When is the last time the plugs have been swapped? If it comes down to it, I'd inspect plugs, replace if needed, recheck, and then move onto inspecting injectors.

[TSHRTS_M4]

Originally Posted by Donteflon

Bank 1 STFT is lean while Bank 2 STFT is right on the money with a great lambda. This supports what heitzke was saying earlier.

Additionally, you're getting timing retardation in Cyls 1-2 which is Bank 1, the same bank where your trims are lean.

I don't think this is a coincidence and there is a correlation.

When is the last time the plugs have been swapped? If it comes down to it, I'd inspect plugs, replace if needed, recheck, and then move onto inspecting injectors.

Plugs were done about 10k miles ago when I did the bolt ons and stage 2 tune ...

[Donteflon]

Originally Posted by TSHRTS_M4

Plugs were done about 10k miles ago when I did the bolt ons and stage 2 tune ...

Ah okay.

Potentially try what was mentioned above perhaps? Can also consult BM3 and have them take a look and see what they advise.

Could be an injector as well as plugs though. I wouldn't rule that out of the realm of possibilities.