Mystery Misfire!

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
Hello, I am having a constant misfire in cylinder 1 after recently changing to NGK 95770 at .020 now .022 and Delphi coils. In the last 2 weeks I have walnut blasted, new valve cover and gasket, new hpfp, moved injectors (all index 12) from 1&2 to 3&4 new decouplers/seals and coded. I've reset adaptations with inpa. Changed from e60 custom tune to MHD OTS pump. Consistent misfire cylinder 1 and lean. O2s/LPFP sensor/Wiring is all I can think of. I did a compression test and compression was good. Someone please help I will attach some logs. Thanks!
http://datazap.me/u/tomhondros/no-misfire
http://datazap.me/u/tomhondros/misfired
http://datazap.me/u/tomhondros/didnt-misfire-was-pulsing
 

doublespaces

General of the Army
Oct 18, 2016
8,943
4,150
0
AZ
Ride
2009 E93 335i
Hello, I am having a constant misfire in cylinder 1 after recently changing to NGK 95770 at .020 now .022 and Delphi coils. In the last 2 weeks I have walnut blasted, new valve cover and gasket, new hpfp, moved injectors (all index 12) from 1&2 to 3&4 new decouplers/seals and coded. I've reset adaptations with inpa. Changed from e60 custom tune to MHD OTS pump. Consistent misfire cylinder 1 and lean. O2s/LPFP sensor/Wiring is all I can think of. I did a compression test and compression was good. Someone please help I will attach some logs. Thanks!
http://datazap.me/u/tomhondros/no-misfire
http://datazap.me/u/tomhondros/misfired
http://datazap.me/u/tomhondros/didnt-misfire-was-pulsing

Have you tried a .018 gap?
 
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1and1

Specialist
Dec 28, 2016
60
34
0
Tally, FL
As I read your OP, all was fine until you swapped in new plugs and coils. You then got consistent misfires in the no.1 cylinder- that about right?

You then list troubleshooting for everything /but/ plugs & cp's, aside from making the plug gap larger so the cp's would have to work even harder.

I'd strongly encourage trying a smaller gap first like suggested above, then,if the symptom persists, swapping the no.1 & no.3 cp to see if the problem follows the cp.

Not much to go on here, but my money is on the Delphi CP being weak.
 

[email protected]

Lieutenant
Nov 14, 2016
655
261
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North Wilkesboro
As I read your OP, all was fine until you swapped in new plugs and coils. You then got consistent misfires in the no.1 cylinder- that about right?

You then list troubleshooting for everything /but/ plugs & cp's, aside from making the plug gap larger so the cp's would have to work even harder.

I'd strongly encourage trying a smaller gap first like suggested above, then,if the symptom persists, swapping the no.1 & no.3 cp to see if the problem follows the cp.

Not much to go on here, but my money is on the Delphi CP being weak.

Correct, with all the things considered. The first things to check when it comes to a missfires is the most critical pieces to the combustion cycle.

We all know what a missfires is but, there's only a select amount of elements that could be to blame in the process.

Power and fueling are the main to ingredients to make this process work. If your fuel pressure across low and high pressure systems are good then, check the injectors. Common signs of a failing injector is either

A) pull the spark plugs and if they smell like gas or you receive rough starts then you found a problem! (This also lets you see if the spark plugs are okay anyways)

B) in logs you'll notice trends across one bank or both banks that the AFR is deviating from Target either during spool or during high RPM. (Timing corrections may also follow this trend and, you can resolve those possibly as well)

While you have the spark plugs out check the inside of the coilpacks for and debris or corrosion.

If all else fails as mentioned swap the CPs around and see if the trend follows.

Once all of these things are done then you still have some options of things to go trough from bad oil filters causing VANOS issues to possible mosefets failure.
 
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tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
Got my mosfets tested today all good. Will try the .018 gap. I have swapped coils and plugs around so many times it doesn't follow as well as injectors. I will try the gap if not I'm gonna try a buddys spark plug set. Reason I increased gap is because I went from e60 to pump so figured the smaller gap wasn't necessary.
 

[email protected]

Lieutenant
Nov 14, 2016
655
261
0
North Wilkesboro
Got my mosfets tested today all good. Will try the .018 gap. I have swapped coils and plugs around so many times it doesn't follow as well as injectors. I will try the gap if not I'm gonna try a buddys spark plug set. Reason I increased gap is because I went from e60 to pump so figured the smaller gap wasn't necessary.
Does all of the wiring and connections look good for the cylinders giving you issues?
 

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
Does all of the wiring and connections look good for the cylinders giving you issues?
Yeah I had to reground 1&2 cylinder ground with a ring connector but got it down. The car runs so smooth under 4k I can see the plugs being bad even tho there 3k miles ago I gapped them so many different times could've damaged the electrodes
 

[email protected]

Lieutenant
Nov 14, 2016
655
261
0
North Wilkesboro
Yeah I had to reground 1&2 cylinder ground with a ring connector but got it down. The car runs so smooth under 4k I can see the plugs being bad even tho there 3k miles ago I gapped them so many different times could've damaged the electrodes
Be very careful when doing that because, there is the possibility that over time with all the heat and pressure that is on them during heavy load that if the physical strength is weakened it could fail or ultimately brake.

Do you have your old spark plugs still? You could swap those back in and, see what happens.
 

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
Understood will constantly check on it. Do not have the old plugs or would've tried already. I was running Bosch and they were great I did a bunch of maintenance prepping for turbo upgrade and the NGKs might just not mix..

Be very careful when doing that because, there is the possibility that over time with all the heat and pressure that is on them during heavy load that if the physical strength is weakened it could fail or ultimately brake.

Do you have your old spark plugs still? You could swap those back in and, see what happens.
nders
 

[email protected]

Lieutenant
Nov 14, 2016
655
261
0
North Wilkesboro
Understood will constantly check on it. Do not have the old plugs or would've tried already. I was running Bosch and they were great I did a bunch of maintenance prepping for turbo upgrade and the NGKs might just not mix..


nders

Which NGKs do you have? I have 5992s on my personal car (Gapped to .020) Bosch Coils though.. I've never heard anything horrible about Delphi coils so, possibly just a bad set? No other error messages or anything?
 

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
Which NGKs do you have? I have 5992s on my personal car (Gapped to .020) Bosch Coils though.. I've never heard anything horrible about Delphi coils so, possibly just a bad set? No other error messages or anything?
Also have 5992s were gapped at .020 and misfiring on 20ish psi on stockers. I have even put a tested working coil in 1 and still misfires there. It is constantly 1 maybe because its the first cylinder but I will try regapping them to .018
 

R.G.

Lieutenant
Nov 17, 2016
669
325
0
Henderson, NV
Ride
E92 335, F10 M5
My car seemed to dislike the NGKs and were always problematic. I've been running Brisk QR12LS plugs and have loved them.

ST 21psi ~10k miles .022 E50 on the ones pictured. They're expensive unfortunately and require a different ultra thin socket
IMG_6204.JPG
 

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
My car seemed to dislike the NGKs and were always problematic. I've been running Brisk QR12LS plugs and have loved them.

ST 21psi ~10k miles .022 E50 on the ones pictured. They're expensive unfortunately and require a different ultra thin socket
Good find Will definitely look into it as I am going ST shortly
 

Bmwfixerguy1

Lieutenant
Jun 5, 2017
873
288
0
Ride
07 335i MT
Check dme connection.. I've had a few now where water gets I to the ebox from an improperly installed ebox cover.. We are in and out so much with the advent of the jb4 that they get I stalled poorly and get water in them.. Bam horribly corroded dme connections and both of them were misfires
 

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
Pulled and opened it yesterday all looked well ordered a set of bosch plugs ran those b4 with no misfire as soon as I switched misfire. Hoping it fixes my issue
Check dme connection.. I've had a few now where water gets I to the ebox from an improperly installed ebox cover.. We are in and out so much with the advent of the jb4 that they get I stalled poorly and get water in them.. Bam horribly corroded dme connections and both of them were misfires
d
 

08_335i

Sergeant
Nov 3, 2016
372
217
0
28
Ride
2008 ST 335i
Pulled and opened it yesterday all looked well ordered a set of bosch plugs ran those b4 with no misfire as soon as I switched misfire. Hoping it fixes my issue
d
I'm not sure why, but on stock turbos my car misfired like crazy above 4k rpms with the NGK's, Bosch's ran like champs. But now with my ST it absolutely loves the NGK's.
 

tommyhondros

Specialist
Jul 16, 2017
62
14
0
Ride
e92 335xi coupe
I'm not sure why, but on stock turbos my car misfired like crazy above 4k rpms with the NGK's, Bosch's ran like champs. But now with my ST it absolutely loves the NGK's.
Same here I get the new plugs in a day or so if that fixes the issue will be kinda mad of all the time/money I've put in but atleast everything maintenance wise is covered.