S55 F82 very bad misfire issue

[rafaeliskander]

I don’t think JB4 is the problem could be but I’m getting the same issues in Cylinder 2,3,4 and same with the DT malfunction and flashing CEL. I’m tuned in Stg 2 91 ACN on BM3. The shop told me to do injectors and coil packs but I don’t think it’s that. I already did injector 4 and coil pack 4 so it wouldn’t make sense that cylinder 4 is misfiring cause bad injectors or coil pack. It’s only been like 1000 miles

[nguksi]

Hi,
hope you came right and what were your findings ?
I have a similar issue, car is completely stock I had to replace the VALVE cover on my F82 S55, after replacement drove the car but as i was driving uphill stepped full throttle got error car went into limp mode, restarted the car things were back to normal but everytime i stepped on the gas in high gears i got the same issue, replaced plugs, still the same problem diagnostic reports Cylinder misfires on CYL 2 and 5, swapped coil packs around same symptoms, now I am suspecting High pressure fuel pump, how can i test this before I purchase a new one ?

[tomlong]

I recently started running F10 M5 EU5 injectors along with 100% meth injection on stock turbos approx. 2-months ago. Car ran like a beast up until 3-weeks ago when I too experienced very similar symptoms as described earlier in this thread.

My DTC fault codes generated, however, were the ones that read "combustion dropouts across multiple cylinders" and specifically "cylinder 4" while my datalogging dashboard showed the car registered as high as 20+ misfires for cylinder 4 in particular under its misfire counter data log parameter when this happens in real-time.

For me, this would occur upon dropping the hammer (and similar to your descriptions) my car would immediately go into limp mode. I would pull over as soon as I could and turned the motor off right away. Let it rest for 30-45mins before firing it back up to drive normal home in which case the car drove just fine, as if nothing happened.

Picking the car up later today from my performance shop who indicated it was a faulty fuel injector in cylinder 4 and suspect the electronic component of the injector was what specifically failed. They believe there's been a bad batch of these OEM EU5 injectors going around lately because another F8x from the same shop I was told had two EU5 injectors put in around the same time also go faulty. When asked, the vendor who supplied these injectors confirmed that we aren't the only ones who received a bad batch as complaints from multiple parties surfaced.

Fingers crossed this issue will be finally resolved for me. It's definitely one of the scariest feelings I've experienced with this otherwise super reliable motor. Will report back should my same issues persist but I'm really hoping it has passed.

[Simon P.]

Originally Posted by tomlong

I recently started running F10 M5 EU5 injectors along with 100% meth injection on stock turbos approx. 2-months ago. Car ran like a beast up until 3-weeks ago when I too experienced very similar symptoms as described earlier in this thread.

My DTC fault codes generated, however, were the ones that read "combustion dropouts across multiple cylinders" and specifically "cylinder 4" while my datalogging dashboard showed the car registered as high as 20+ misfires for cylinder 4 in particular under its misfire counter data log parameter when this happens in real-time.

Tom,
How did this resolve itself? Did changing out the faulty injector correct the issue? I'm on EU5's, currently tuning for Kratos EVO's and having the same exact codes but for cyl. 6.
Tx

[deli333]

did you try cleaning maf or replacing pre oxygen sensors?

[tomlong]

Originally Posted by Simon P.

Tom,
How did this resolve itself? Did changing out the faulty injector correct the issue? I'm on EU5's, currently tuning for Kratos EVO's and having the same exact codes but for cyl. 6.
Tx

Turns out it was caused by my damaged flywheel wobbling around and resulting in the crank sensor not being able to get signal readings. Out of all the places to diagnose, who would've thought 🤷*♂️

[Simon P.]

Originally Posted by tomlong

Turns out it was caused by my damaged flywheel wobbling around and resulting in the crank sensor not being able to get signal readings. Out of all the places to diagnose, who would've thought 🤷*♂️

Lol that's a new one.
For me the tuners think they know what's going on but chose not to elaborate too much.
I pulled the plugs and everything is fine (gap, ceramics) and I reinstalled plug and coil from #6 (where the fault originated) into hole #1 for ease of access in the event the fault moved. About a week later the fault reapeared under the same conditions (WOT pull in 4th, way up around 7kRPM), still at #6 so clearly not a coil or plug problem. I'm letting Bend do their thing, they've been on top of things from the begining so I'm not too worried at this point. To be safe though, I bought a spare EU5 injector that I can swap in and code if needed.

[tomlong]

Originally Posted by Simon P.

Lol that's a new one.
For me the tuners think they know what's going on but chose not to elaborate too much.
I pulled the plugs and everything is fine (gap, ceramics) and I reinstalled plug and coil from #6 (where the fault originated) into hole #1 for ease of access in the event the fault moved. About a week later the fault reapeared under the same conditions (WOT pull in 4th, way up around 7kRPM), still at #6 so clearly not a coil or plug problem. I'm letting Bend do their thing, they've been on top of things from the begining so I'm not too worried at this point. To be safe though, I bought a spare EU5 injector that I can swap in and code if needed.

So I did replace one of the EU5 injectors but the issue persisted (obviously) … if you have the Ecutek dashboard display misfire parameters for each of the 6 cylinders that might also help to determine which cylinder-specific or not these misfires are occurring within.

[Simon P.]

Originally Posted by tomlong

So I did replace one of the EU5 injectors but the issue persisted (obviously) … if you have the Ecutek dashboard display misfire parameters for each of the 6 cylinders that might also help to determine which cylinder-specific or not these misfires are occurring within.

Cylinder #6 was the only affected cylinder on both events but I like the idea, I'm going to set up a new dashboard to show only the misfire count.
Tx