Log File with Misfires

N54TT

Corporal
Jul 21, 2020
136
41
0
Ride
2013 335is
2013 BMW 335is DCT
RB GF 17T TD04 turbos
Inlets/Outlets
DP's + 3.5" Exhaust
BMP Stage 3 LPFP with BMP Port Injection
Full E85
XHP Stage 3
CTS IC, etc, etc, etc

Maintenance:
Index 12's
OEM HPFP
RB PCV
OEM valve cover
4 Bosch Oxygen Sensors
NGK 2-step @ .020" with PR coils

I have misfire detection turned off from 6000+ RPM just to figure out why my car still triggers a misfire on Cylinder 6 and some times Cylinder 5 & 6 at the same time. I noticed bank 2 STFT pegs out around -30 in the mid range and picked up towards the higher RPM. I'm also on the process of having my HPFP swapped by FCP Euro because I made a thread last week on my rail pressure randomly dipping and based on Precision Raceworks opinion they suggested that I replace the HPFP. I attached a photo of a screenshot and I noticed at 6,666 rpm the AFR on Bank 2 is lean, but I can't tell if that's after the misfire or before the misfire because the rail pressure is still reading above 2000 psi and the throttle is still at 81.
 
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BloodyZ4

Lurker
Mar 17, 2021
17
6
0
Germany
Ride
Z4 35i DCT
I'm battling the same problem right now :O how did you disable misfires after 6000 RPM ? Is this log with it disabled and it still misfires?
Your AFR goes lean the same time as the misfire occurs you can see the fuel mode going 15 which is open loop.
Like you noticed your stft are way off, looks like PI isn't properly setup or your injectors acting up. Otherwise your log looks pretty clean in my opinion.
Just like mine. I can't see any obvious reason why it misfires in my log either, it's really frustrating.
I've read the dual mass flywheel might be causing noise and triggering a misfire, chaning that for the M4 one has fixed the issue for some people.

 
Last edited:

N54TT

Corporal
Jul 21, 2020
136
41
0
Ride
2013 335is
I'm battling the same problem right now :O how did you disable misfires after 6000 RPM ? Is this log with it disabled and it still misfires?
Your AFR goes lean the same time as the misfire occurs you can see the fuel mode going 15 which is open loop.
Like you noticed your stft are way off, looks like PI isn't properly setup or your injectors acting up. Otherwise your log looks pretty clean in my opinion.
Just like mine. I can't see any obvious reason why it misfires in my log either, it's really frustrating.
I've read the dual mass flywheel might be causing noise and triggering a misfire, chaning that for the M4 one has fixed the issue for some people.


I thought misfire was turned off after 6000+ RPM, but it was not. This log attached is with misfire detection turned off and it worked fine, but I would hate to have it off in the higher RPM in-case there really is a problem. I do have a M4 flywheel that needs to be installed so hopefully that does resolve the issue. As far as my port setup and STFT it might be from the AIC map with a lot of added fuel before we figured out the HPFP is failing and needs to be replaced even though its brand new lol or possibly the bank 2 pre-cat oxygen sensor since that one keeps throwing faults or maybe the new index 12's in bank 2 are bad which I can always swap banks around and see what happens. I have heard quite a few times about a bad batch of index 12's out the box going around. It could be A LOT of things with the N54 lol :sweatsmile:
 
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BloodyZ4

Lurker
Mar 17, 2021
17
6
0
Germany
Ride
Z4 35i DCT
Keen to see if the M4 flywheel fixes the misfire.
I did have one new faulty Index 12 Injector myself, idle was still rough after replacing all 6 lol :D
So worth a try swapping bank 1 and bank 2 around. STFT's should follow, or try swapping your o2's first before touching the injectors.
Yeah N54 is big headache time :D

Does anyone know how to switch Misfires off after 6000 RPM? Maybe @carabuser @RSL
I've tried using the toggle in the public XDF but it didn't make a difference.
 

Threetirtyfive

Corporal
Jan 9, 2019
135
68
0
Ride
335i
2013 BMW 335is DCT
RB GF 17T TD04 turbos
Inlets/Outlets
DP's + 3.5" Exhaust
BMP Stage 3 LPFP with BMP Port Injection
Full E85
XHP Stage 3
CTS IC, etc, etc, etc

Maintenance:
Index 12's
OEM HPFP
RB PCV
OEM valve cover
4 Bosch Oxygen Sensors
NGK 2-step @ .020" with PR coils

I have misfire detection turned off from 6000+ RPM just to figure out why my car still triggers a misfire on Cylinder 6 and some times Cylinder 5 & 6 at the same time. I noticed bank 2 STFT pegs out around -30 in the mid range and picked up towards the higher RPM. I'm also on the process of having my HPFP swapped by FCP Euro because I made a thread last week on my rail pressure randomly dipping and based on Precision Raceworks opinion they suggested that I replace the HPFP. I attached a photo of a screenshot and I noticed at 6,666 rpm the AFR on Bank 2 is lean, but I can't tell if that's after the misfire or before the misfire because the rail pressure is still reading above 2000 psi and the throttle is still at 81.

It looks like possibly a leaky injector on bank 2.

Can you do an off throttle log, eg, accelerate full load to say 4krpm, then back off and log all the time including as you are completely off throttle?


It is also possible that bank 2 is dumping a load of fuel as a result of the misfire but more logs are needed.
 
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RSL

Lieutenant
Aug 11, 2017
838
449
0
Keen to see if the M4 flywheel fixes the misfire.
I did have one new faulty Index 12 Injector myself, idle was still rough after replacing all 6 lol :D
So worth a try swapping bank 1 and bank 2 around. STFT's should follow, or try swapping your o2's first before touching the injectors.
Yeah N54 is big headache time :D

Does anyone know how to switch Misfires off after 6000 RPM? Maybe @carabuser @RSL
I've tried using the toggle in the public XDF but it didn't make a difference.
Look for a misfire max RPM table in the XDF and try that. I think DCT shares the MT for that one.
 
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SLOWESTN54

Lieutenant
Feb 9, 2021
738
477
0
22
B.C. Canada
Ride
2007 E92 335i / 2008 E60 535i
I thought misfire was turned off after 6000+ RPM, but it was not. This log attached is with misfire detection turned off and it worked fine, but I would hate to have it off in the higher RPM in-case there really is a problem. I do have a M4 flywheel that needs to be installed so hopefully that does resolve the issue. As far as my port setup and STFT it might be from the AIC map with a lot of added fuel before we figured out the HPFP is failing and needs to be replaced even though its brand new lol or possibly the bank 2 pre-cat oxygen sensor since that one keeps throwing faults or maybe the new index 12's in bank 2 are bad which I can always swap banks around and see what happens. I have heard quite a few times about a bad batch of index 12's out the box going around. It could be A LOT of things with the N54 lol :sweatsmile:

there's a few simple things you could try. Looking at the log closely almost seems that your Bank 2 Stfts start veering off when your PI turns on. Possible a sticking or a leaking PI injector. You could have them cleaned and flow tested. @carabuser was great help with my car.
 

carabuser

Lieutenant
Oct 2, 2019
549
1
410
0
UK
Ride
Z4 35i & 335i
I thought misfire was turned off after 6000+ RPM, but it was not. This log attached is with misfire detection turned off and it worked fine, but I would hate to have it off in the higher RPM in-case there really is a problem. I do have a M4 flywheel that needs to be installed so hopefully that does resolve the issue. As far as my port setup and STFT it might be from the AIC map with a lot of added fuel before we figured out the HPFP is failing and needs to be replaced even though its brand new lol or possibly the bank 2 pre-cat oxygen sensor since that one keeps throwing faults or maybe the new index 12's in bank 2 are bad which I can always swap banks around and see what happens. I have heard quite a few times about a bad batch of index 12's out the box going around. It could be A LOT of things with the N54 lol :sweatsmile:

In that log there's certainly something wrong on bank 2. I have no experience with port injection but that would be my first suspicion. You can see that the port injection is still supplying fuel when injection is cut off after the pull and bank 2 is much richer. You could try taking the tune down to a level where PI can be disabled and see if the problem is still present.

I'd also point the tuner towards getting the shifts tightened up. Your timing is pulled for half a second as the gearbox isn't reporting a complete shift. You can also see the fuel cut during the shift where trims go to 0, the DME only cuts fuel like that when the torque reduction from the DME is higher than the minimum available torque that is capable via ignition reduction alone.
 
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BloodyZ4

Lurker
Mar 17, 2021
17
6
0
Germany
Ride
Z4 35i DCT
Look for a misfire max RPM table in the XDF and try that. I think DCT shares the MT for that one.
Damn I'm literally blind, I just saw the one toggle for disabling misfire for a specific bank under "Toggles - Functions", which didn't do anything.
The correct one was under "WIP - Testing" and worked fine.
 
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N54TT

Corporal
Jul 21, 2020
136
41
0
Ride
2013 335is
I'd also point the tuner towards getting the shifts tightened up. Your timing is pulled for half a second as the gearbox isn't reporting a complete shift. You can also see the fuel cut during the shift where trims go to 0, the DME only cuts fuel like that when the torque reduction from the DME is higher than the minimum available torque that is capable via ignition reduction alone.

Thank You. Could the DCT XHP Torque Reduction settings have anything to do with it? I did increase the torque reduction when I felt those "spongy delayed" shifts.
 

zaw111

Specialist
Oct 2, 2019
66
13
0
St-Petersburg
Ride
Zxcvbnm1
I think the first thing to do is swap the spark plugs and coils. For example 5 and 6 with 1 and 2 . If nothing changes (missfires will not go to 1 and 2) , swap the injectors in the same way. Correction of 5 on logs is too big
 

carabuser

Lieutenant
Oct 2, 2019
549
1
410
0
UK
Ride
Z4 35i & 335i
Thank You. Could the DCT XHP Torque Reduction settings have anything to do with it? I did increase the torque reduction when I felt those "spongy delayed" shifts.
No, that torque reduction slider doesn't do a lot. If you set it to 0 the trans will still request a timing pull, it's just some kind of factor that has a small effect on the reduction value.