High rpm misfire, always cyl 6 - JB4tech.com

SpoolnMS · 06:13 AM

I've been battling this issue for awhile and replaced damn near everything. Car is pulling timing and has a cyl6 misfire. Inj are new index 12, new hpfp, dual 450 lpfp, Franken turbos, relocated inlets, mmp outlets, pr coils, new ngk gapped at .022 (smaller gap dosnt make a difference either). vrsf charge pipe and race ic, pi, etc. All maintenance is done

Swapped coils, plug wires, injectors and issue does not follow. Still cyl6, sometimes 5 but very rare. Fueling is fine, and no matter what we do it always misfires. Compression and leak down are good too. Car is also an auto (08 335i). Misfires around 6300-6500

Can it be the stock tc causing issues? I'm running e90, kinda wanna try disabling misfire detection or slightly desensitize knock tables (as I'm pretty sure its phantom knock/misfire) above 6k as its e90 (hard to knock). Any advice? Tired of throwing money into it replacing every part without resolving.

https://drive.google.com/file/d/19Cr...w?usp=drivesdk

THE BEAST · 09-29-2018, 09:26 PM

Csv file ?

SpoolnMS · 09-30-2018, 06:05 AM

Can download it with that link too

Dave @ BMS/Fuel-It! · 09-30-2018, 11:15 AM

Quote:

Originally Posted by SpoolnMS

I've been battling this issue for awhile and replaced damn near everything. Car is pulling timing and has a cyl6 misfire. Inj are new index 12, new hpfp, dual 450 lpfp, Franken turbos, relocated inlets, mmp outlets, pr coils, new ngk gapped at .022 (smaller gap dosnt make a difference either). vrsf charge pipe and race ic, pi, etc. All maintenance is done

Swapped coils, plug wires, injectors and issue does not follow. Still cyl6, sometimes 5 but very rare. Fueling is fine, and no matter what we do it always misfires. Compression and leak down are good too. Car is also an auto (08 335i). Misfires around 6300-6500

Can it be the stock tc causing issues? I'm running e90, kinda wanna try disabling misfire detection or slightly desensitize knock tables (as I'm pretty sure its phantom knock/misfire) above 6k as its e90 (hard to knock). Any advice? Tired of throwing money into it replacing every part without resolving.

https://drive.google.com/file/d/19Cr...w?usp=drivesdk

Just upload the csv file. We don’t use 3rd party / host sites

SpoolnMS · 04:33 PM

Attached is the csv

Haynpunch · 09-30-2018, 03:26 PM

Looks like HPFP can't keep up

i could be wrong..

cebrailbakan · 09-30-2018, 03:47 PM

What I see in the log is that Hpfp flows intermittently

SpoolnMS · 09-30-2018, 04:14 PM

Oops wrong log. Here it is. I get random cyl5 timing drops, I'm calling gphantom knock.

SpoolnMS · 09-30-2018, 04:37 PM

After disabling misfire above 6k it pulls good. Except for the timing drop on 5. Now that I think about it, I did add poly trans mounts and logs before them didnt have timing drops. . . Hmm wonder if I still have my stock trans mounts

Payam @ BMS · 10-01-2018, 07:10 AM

5 is definitely having a hard time. How old are you coils and plugs, what gap?

SpoolnMS · 10-01-2018, 02:25 PM

Coils are precision coils, and plugs are brand new ngk .022. Tried .018 and .020 with no difference

Dave @ BMS/Fuel-It! · 10-01-2018, 10:49 PM

Quote:

Originally Posted by SpoolnMS

Coils are precision coils, and plugs are brand new ngk .022. Tried .018 and .020 with no difference

Could try throwing in the stock mounts, see if that’s causing any false knock.

SpoolnMS · 09:56 AM

Quote:

Originally Posted by Dave @ Fuel-it!

Could try throwing in the stock mounts, see if that’s causing any false knock.

Put the stock mounts back in, and its still pulling timing but not as much. Also the car is adding timing back in toward the top end, which that right there is telling me its not real knock (nothing I didnt really know). So something somewhere is messing with the knock sensor.

I have a feeling its the relocated inlets as i did not remove the heatshield and I know for a fact its hitting/rubbing. When I pulled the plugs out the 1000000 time, all of them looked perfect. So that again verify's the engine isnt knocking.

So back on point, after disabling misfire detection on cyl5 above 6k (as well as changing cyl5 pr coil to cyl1) the misfire went away on 6 and came misfired on 1. Was like wtf, it never misfired on 1 before. And the ONLY thing I did not change was coils (had pr coils, didnt think of it). Bought new stock coils, regapped the plugs to .020 and bam no more misfire. Still get timing drop on 5 but not as bad as it was.

DSCOFF · 10-02-2018, 05:46 PM

Quote:

Originally Posted by SpoolnMS

I've been battling this issue for awhile and replaced damn near everything. Car is pulling timing and has a cyl6 misfire. Inj are new index 12, new hpfp, dual 450 lpfp, Franken turbos, relocated inlets, mmp outlets, pr coils, new ngk gapped at .022 (smaller gap dosnt make a difference either). vrsf charge pipe and race ic, pi, etc. All maintenance is done

Swapped coils, plug wires, injectors and issue does not follow. Still cyl6, sometimes 5 but very rare. Fueling is fine, and no matter what we do it always misfires. Compression and leak down are good too. Car is also an auto (08 335i). Misfires around 6300-6500

Can it be the stock tc causing issues? I'm running e90, kinda wanna try disabling misfire detection or slightly desensitize knock tables (as I'm pretty sure its phantom knock/misfire) above 6k as its e90 (hard to knock). Any advice? Tired of throwing money into it replacing every part without resolving.

https://drive.google.com/file/d/19Cr...w?usp=drivesdk

I have been battling this issue for over a year and like you replaced everything under the sun to no avail until about 3 months ago we finally saw the light on this. However I changed two parts at the same time so it could be either or both being the culprit. I changed the PI gaskets in the manifold and bigger Pi injectors 750cc. Also found s couple of my 500cc Pi injectors had been leaky when replacing them. But I would say cyl 6 misfires related to the PI. Any sudden spikes affecting the hpfp and the dme does not like it.

Dave @ BMS/Fuel-It! · 10-02-2018, 10:36 PM

Quote:

Originally Posted by SpoolnMS

Put the stock mounts back in, and its still pulling timing but not as much. Also the car is adding timing back in toward the top end, which that right there is telling me its not real knock (nothing I didnt really know). So something somewhere is messing with the knock sensor.

I have a feeling its the relocated inlets as i did not remove the heatshield and I know for a fact its hitting/rubbing. When I pulled the plugs out the 1000000 time, all of them looked perfect. So that again verify's the engine isnt knocking.

So back on point, after disabling misfire detection on cyl5 above 6k (as well as changing cyl5 pr coil to cyl1) the misfire went away on 6 and came misfired on 1. Was like wtf, it never misfired on 1 before. And the ONLY thing I did not change was coils (had pr coils, didnt think of it). Bought new stock coils, regapped the plugs to .020 and bam no more misfire. Still get timing drop on 5 but not as bad as it was.

PR coils have failed me. . .

Cyl 5 is notoriously noisy..

If you want- desensitize the sensors in MHD flash options & log. See if that cleans up cyl 5..

If it does, it’s a personal preference if you want to run around with the sensors numbed...just use your best judgement.

SpoolnMS · 10-03-2018, 04:53 AM

That is the next option, except just cyl5. Its e90, I feel comfortable with a slight reduction in knock sensor sensitivity. I'll give that a try and see.

StormShadow335 · 06-25-2020, 07:44 PM

Quote:

Originally Posted by SpoolnMS

That is the next option, except just cyl5. Its e90, I feel comfortable with a slight reduction in knock sensor sensitivity. I'll give that a try and see.

How did this turn out for you? I'm also having issues with timing drops at higher rpms and on shifts.