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.