Inconsistent timing on one or more cylinders

[Nicks_M3]

Hey everyone!

This is my first post in this forum, I bought my F82 M4 in December 2020. I've already done some mods with plenty more on the way.

So as soon as I picked up the car, I flashed bootmod3 stage 0 gts software. I did some data logs with bootmod3 and noticed some inconsistencies with my timing. Cylinder 4 and 6 seemed to be slightly off by about 4 to 6 degrees from the rest of the car. No problem I thought, I had just past 30k miles so I decided to do new plugs (ngk laser iridium gapped to .022) when I installed my down pipes and I figured that it would most likely solve my problem. Fast forward to yesterday and I decided to log again on stage 2 93 octane and noticed cylinder 4 and 6 again pulling timing. Today was a nice day so I figured I would check the coils to see if they were the culprit. As I didn't want to take the aluminum brace off I just swapped 4 with 3. I also noticed the rubber hose on the charge pipe was melting on to the clamps and pipe itself (not sure if anyone else has had that issue?) so perhaps new charge pipes and a meth system is in order. Anyways back to the data log and I decided to run some logs today. Same issue with 4 and 6 so I can scratch coils off the list as well.

Hopefully anyone here can chime in and tell me if what I'm seeing is normal or if there's potentially an underlying issue. I was running 94 octane on the stock 91 tune and since it's the same 2 cylinders I can probably scratch fuel quality off the list? Spark plugs were changed and I swapped coils to see if it would follow to no avail. My next step is injectors but as I do with any car I buy, I run injector cleaner through the system so I can't imagine there being a problem with those at the moment either. The logs taken from today are posted below. I can provide the older logs but I'm still a noob at data logging and finding a safe place to do 100+mph pulls so the older ones aren't really up to par.


https://www.bootmod3.net/log?id=6052...90c65d1b463305

https://www.bootmod3.net/log?id=6052...0b43132a43027e

Thanks for all the help and suggestions everyone, I'm currently buying a few parts so I'm sure I'll be speaking with some of you on the sales forum in the near future!

[TideMD]

I can't help out with a cause or any other insightful info. But, I get the same issue with cyl4 and only with cyl4. It routinely runs a few degrees below the other 5.

So far, the trend has held true running stock map, OTS 93 tune, and custom 93 and E85 tunes.
I've had fresh plugs and coils installed and still saw no change in the timing for cyl4 being consistently lower than the others. Even went so far as to swap plugs and coils between cyl4 and cyl1, with absolutely no change in the timing curves.

At this point, I've just accepted it as an idiosyncrasy of my car and will overlook it, as long as no obvious performance degradation is occurring.

[sly1types]

Its not knocking, but it does drop down and fall behind, but at least it keeps climbing. Sometimes plugs help, but mine will do this sometimes on pump gas also, even with 93 in the tank of the 91 or GTS tunes. My guess its just that injector is a little less flow..

[tomlong]

OP - I'm sorry but those logs are impossible for me to read. Bootmod3 should re-evaluate the user interface.

Ignition timing should never be off. Even with worn or non-fresh spark plugs. But if no real performance degradation exists, as mentioned above, then I would perhaps look at whether or not the issue maybe sensor or electrical signal/connection related.

Ignition timing should look 100% in lock step across all 6 cylinders. User interface is Ecutek.

https://www.instagram.com/s/aGlnaGxp...09017265489150

[e46m3to335i]

OP did you ever get this resolved?

I’m experiencing the same issue as the OP. Cylinder 4 is always 3-4 degrees lower than the rest of the cylinders. I’m currently running the BM3 flex fuel multi map with E45 in the tank. Cylinder 4 has always been lower than the rest regardless of what map it’s on or the fuel being used.

[ALCOBENDAS]

Other cyl 4 pulling..

[hellokitty]

Is Traction control turned on? What if you switch it off and see if it goes away?

[e46m3to335i]

Originally Posted by hellokitty

Is Traction control turned on? What if you switch it off and see if it goes away?

Traction control is turned completely off on mine during the logs that show timing being lower on cylinder 4

[hellokitty]

Originally Posted by e46m3to335i

Traction control is turned completely off on mine during the logs that show timing being lower on cylinder 4

Pull the spark plug on 4 and check the gap again? What about comparing the cyl 4 to cyl 3? Any abnormalities?

I see timing corrections randomly as well but my actual load is very close to target load so I don't think things are too off.

[RichardM4]

Originally Posted by Nicks_M3

Hey everyone!

This is my first post in this forum, I bought my F82 M4 in December 2020. I've already done some mods with plenty more on the way.

So as soon as I picked up the car, I flashed bootmod3 stage 0 gts software. I did some data logs with bootmod3 and noticed some inconsistencies with my timing. Cylinder 4 and 6 seemed to be slightly off by about 4 to 6 degrees from the rest of the car. No problem I thought, I had just past 30k miles so I decided to do new plugs (ngk laser iridium gapped to .022) when I installed my down pipes and I figured that it would most likely solve my problem. Fast forward to yesterday and I decided to log again on stage 2 93 octane and noticed cylinder 4 and 6 again pulling timing. Today was a nice day so I figured I would check the coils to see if they were the culprit. As I didn't want to take the aluminum brace off I just swapped 4 with 3. I also noticed the rubber hose on the charge pipe was melting on to the clamps and pipe itself (not sure if anyone else has had that issue?) so perhaps new charge pipes and a meth system is in order. Anyways back to the data log and I decided to run some logs today. Same issue with 4 and 6 so I can scratch coils off the list as well.

Hopefully anyone here can chime in and tell me if what I'm seeing is normal or if there's potentially an underlying issue. I was running 94 octane on the stock 91 tune and since it's the same 2 cylinders I can probably scratch fuel quality off the list? Spark plugs were changed and I swapped coils to see if it would follow to no avail. My next step is injectors but as I do with any car I buy, I run injector cleaner through the system so I can't imagine there being a problem with those at the moment either. The logs taken from today are posted below. I can provide the older logs but I'm still a noob at data logging and finding a safe place to do 100+mph pulls so the older ones aren't really up to par.


https://www.bootmod3.net/log?id=6052...90c65d1b463305

https://www.bootmod3.net/log?id=6052...0b43132a43027e

Thanks for all the help and suggestions everyone, I'm currently buying a few parts so I'm sure I'll be speaking with some of you on the sales forum in the near future!

Hello, I have a very similar problem. I bought BM3 at the beginning of this year and started tuning. I only use OEM M4 CS or M4 GTS maps. Several weeks ago I started using the datalogs. I noticed that there is a difference in ignition timing. Not only one cillinder but all of them are alternate/changing in a range of 3 degrees, sometimes up to 5 degrees. Mostly in low RPM when there is some fast change. I asked guys from PTF for help, they said that the problem is low fuel quality. So I tried 95, 98 and also 100 OCT fuel and the same problem is still vissible.
Does anyone can help with this issue?

[RichardM4]

Hello,
I have a very similar problem. I bought BM3 at the beginning of this year and started tuning. I only use OEM M4 CS or M4 GTS maps. Several weeks ago I started using the datalogs. I noticed that there is a difference in ignition timing. Not only one cillinder but all of them are alternate/changing in a range of 3 degrees, sometimes up to 5 degrees. Mostly in low RPM when there is some fast change. I asked guys from PTF for help, they sait that the problem is low fuel quality. So I tried 95, 98 and also 100 OCT fuel and the same problem is still vissible.
Does anyone can help with this issue?

[hellokitty]

Originally Posted by RichardM4

Hello,
I have a very similar problem. I bought BM3 at the beginning of this year and started tuning. I only use OEM M4 CS or M4 GTS maps. Several weeks ago I started using the datalogs. I noticed that there is a difference in ignition timing. Not only one cillinder but all of them are alternate/changing in a range of 3 degrees, sometimes up to 5 degrees. Mostly in low RPM when there is some fast change. I asked guys from PTF for help, they sait that the problem is low fuel quality. So I tried 95, 98 and also 100 OCT fuel and the same problem is still vissible.
Does anyone can help with this issue?

You might need to replace spark plugs, change gap and coil packs. That is where I'd start.

[hellokitty]

Originally Posted by RichardM4

Hello,
I have a very similar problem. I bought BM3 at the beginning of this year and started tuning. I only use OEM M4 CS or M4 GTS maps. Several weeks ago I started using the datalogs. I noticed that there is a difference in ignition timing. Not only one cillinder but all of them are alternate/changing in a range of 3 degrees, sometimes up to 5 degrees. Mostly in low RPM when there is some fast change. I asked guys from PTF for help, they sait that the problem is low fuel quality. So I tried 95, 98 and also 100 OCT fuel and the same problem is still vissible.
Does anyone can help with this issue?

Also, keep in mind leaving traction control ON could pull timing.

Always log with DSC OFF.

[MineralWhiteF80]

Originally Posted by RichardM4

Hello,
I have a very similar problem. I bought BM3 at the beginning of this year and started tuning. I only use OEM M4 CS or M4 GTS maps. Several weeks ago I started using the datalogs. I noticed that there is a difference in ignition timing. Not only one cillinder but all of them are alternate/changing in a range of 3 degrees, sometimes up to 5 degrees. Mostly in low RPM when there is some fast change. I asked guys from PTF for help, they sait that the problem is low fuel quality. So I tried 95, 98 and also 100 OCT fuel and the same problem is still vissible.
Does anyone can help with this issue?

There are quite a few threads on this topic. The short story is that nothing actually may be wrong at all with having inconsistent cylinder timing graphs for BootMod3 OTS Stage 1, Stage 2, or flex fuel maps. This seems to be a very common thing with the OTS maps. I've looked through countless BM3 logs on M3Post forums and almost all of them have inconsistent cylinder timing graphs. Most stories consist of, "the car runs perfectly fine, yet the six cylinder ignition timing graphs are not consistent with each other."

Example thread:
https://f80.bimmerpost.com/forums/sh....php?t=2111008

[n8dgr84]

The only reason to be concerned is if the timing pull gets worse as the pull continues and you get Knock.

Knock is really the only thing that does damage and the DME is going to do whatever it takes to prevent that. I've only heard of engine damage from someone who got a Superknock code twice on an OTS map and kept racing at a track day and burnt a piston.

You're more likely to stick an injector open or shut and blow the motor than a couple degrees of timing correction hurting anything.

If you're dead set on extracting every possible HP and eliminating full throttle timing corrections, get the B58 coil kit from Nexsys and run the F8S plugs. I still get part throttle corrections but full throttle is pretty clean.

[Jaizero]

Cylinder 4 pulls timing on mine, too.

This seems to be a common thing with these cars.

[RichardM4]

Thanks for your recomendation. I bought one set of spark plug+coil+injector and exchanged them at the cylinder 4. Then I did another datalog and found out, that the corrections on cyl. 4 are the same as before eventhougt there are a brand new parts.
Is there any another advice/recomendation?
I run stock M4 map, 98 OCT fuel ands here is my last datalog: https://www.bootmod3.net/log?id=66c0...f4f57a429e941a

[RichardM4]

Originally Posted by n8dgr84

The only reason to be concerned is if the timing pull gets worse as the pull continues and you get Knock.

Knock is really the only thing that does damage and the DME is going to do whatever it takes to prevent that. I've only heard of engine damage from someone who got a Superknock code twice on an OTS map and kept racing at a track day and burnt a piston.

You're more likely to stick an injector open or shut and blow the motor than a couple degrees of timing correction hurting anything.

If you're dead set on extracting every possible HP and eliminating full throttle timing corrections, get the B58 coil kit from Nexsys and run the F8S plugs. I still get part throttle corrections but full throttle is pretty clean.

OK understood, but what should I do to stop getting the corections worse?
To change coils to B58 is a good idea but I dont want to ugrade the car to higher level, I only need it works well in stock setting.
Do you have any recomendation what concretely makes the corrections and how can I dispose of them?

[n8dgr84]

Originally Posted by RichardM4

OK understood, but what should I do to stop getting the corections worse?
To change coils to B58 is a good idea but I dont want to ugrade the car to higher level, I only need it works well in stock setting.
Do you have any recomendation what concretely makes the corrections and how can I dispose of them?

I recently spoke with my tuner about this and he said that it's impossible to prevent partial throttle corrections and not to worry because those don't damage the engine.
100% throttle knock count is all you should really worry about and corrections over 5 deg. Here is a good video Ata_T1T made on the subject

[RichardM4]

Originally Posted by n8dgr84

I recently spoke with my tuner about this and he said that it's impossible to prevent partial throttle corrections and not to worry because those don't damage the engine.
100% throttle knock count is all you should really worry about and corrections over 5 deg. Here is a good video Ata_T1T made on the subject

Hello, thank you very much for your interest in my case. Also thanks for the video, very useful for me. My corrections move in range of 0-3, sometimes 0-5 deg. so it should be Ok. Courious is that these inaccuracies I can measure at stock M4 map, what should I expect when I use some more powerfull map, for example Stage 1 map?

People familiar in this topic and experienced tuner says that the main problem is the fuel quality. So I have tried all branded fuel (Shell, Orlen, OMV, MOL) from 95, via 98 to 100 OCT and the result: nothing has changed, random corrections in range of 0-5 deg still visible in the same intensity. It seems that the tuners experience doesnt fit with my home made testing.

You mentioned upgrade coils and spark plugs to B58 version. If I understood well the coils provides higher and stable voltage, colder spark plugs are good for higher RPM but how they behave in standard driving mode?

Thank you, Richard

[NoorSinghJohal]

Originally Posted by n8dgr84

I recently spoke with my tuner about this and he said that it's impossible to prevent partial throttle corrections and not to worry because those don't damage the engine.
100% throttle knock count is all you should really worry about and corrections over 5 deg. Here is a good video Ata_T1T made on the subject

How accurate is the” knock detected” bootmod3 parameter ?

I’ve been getting these on partial throttle on my custom tune but knock voltages don’t seem to increase.

[Jaizero]

Originally Posted by NoorSinghJohal

How accurate is the” knock detected” bootmod3 parameter ?

I’ve been getting these on partial throttle on my custom tune but knock voltages don’t seem to increase.

Partial throttle knock is pretty normal, you'll even see it in the stock tune. It's high load knock or super knock that you want to watch out for.