[WrxToBeamerGuy]

Let me start out by stating that the car drives great and feels great but I love my car so much that this misfire thing is enough for me to chase it to the end of the world and back.

When I start up my car the misfire indicator on Bimmerlink will show a single misfire on any cylinder. Sometimes it shows two (rarely) i.e.

Cyl1: 0
Cyl2: 0
Cyl3: 1
Cyl4: 0
Cyl5: 0
Cyl6: 1

This misfire indicator will happen on any cylinder its not cylinder specific. I don't know I got a misfire because I cant feel it happen.

Next, while cruising around town in low rpms or high rpms I'll get a single misfire indication on any cylinder. Once again I cant feel it and don't know it happened except Bimmerlink says so.

Finally, this misfire happens on all OTS tunes and on the stock tune. BUT it does NOT happen on my custom PJ tune.

New:
Vanos Solenoids
Fuel injectors
Champion plugs gapped to .032
Dinan coil packs
Valve cover
DS2 HPFP

Issue was happening before any of these were replaced. The issue happened with NGK plugs at .022 and .028 as well.

I've tried resetting adaptations in both BM3 and ISTA. In ISTA I've done just the injector adaptation but then I've also tried a full adaptation reset.

I live at high elevation (4,000ft) with only 91 octane available (I use Shell, Chevron, Sinclair).

I had the issue happen with the stock intake and now the dinan intake.

What are some other things I could check that could cause a misfire? I did replace the battery and registered it and programmed it. It's a 95 AH battery and I could only choose to program it as a 90 AH.

Finally, the weirdest part is that Paul Johnsons tune has 0 misfires yet the OEM tune has them and so does the 91 ACN tune.

I'm looking for any sort of insight / thoughts. I'm willing to chase down anything reasonable to get this solved. Attached is a stock log with xhp stage 2 I did this morning of a 4th gear pull.

I should note I have no way of knowing if this log has a misfire since BM3 doesn't have the option to log misfires.

https://www.bootmod3.net/log?id=6258...0b43307c4fa812

Edit: Maybe some of you have this happening too and you don't even know it since, like I said you can't tell its even happening unless you constantly monitor for misfires using Bimmerlink. I'd be curious to know if anyone else has this or if my poor baby is just dying slowly.

[Sensational]

Originally Posted by WrxToBeamerGuy

Let me start out by stating that the car drives great and feels great but I love my car so much that this misfire thing is enough for me to chase it to the end of the world and back.

When I start up my car the misfire indicator on Bimmerlink will show a single misfire on any cylinder. Sometimes it shows two (rarely) i.e.

Cyl1: 0
Cyl2: 0
Cyl3: 1
Cyl4: 0
Cyl5: 0
Cyl6: 1

This misfire indicator will happen on any cylinder its not cylinder specific. I don't know I got a misfire because I cant feel it happen.

Next, while cruising around town in low rpms or high rpms I'll get a single misfire indication on any cylinder. Once again I cant feel it and don't know it happened except Bimmerlink says so.

Finally, this misfire happens on all OTS tunes and on the stock tune. BUT it does NOT happen on my custom PJ tune.

New:
Vanos Solenoids
Fuel injectors
Champion plugs gapped to .032
Dinan coil packs
Valve cover
DS2 HPFP

Issue was happening before any of these were replaced. The issue happened with NGK plugs at .022 and .028 as well.

I've tried resetting adaptations in both BM3 and ISTA. In ISTA I've done just the injector adaptation but then I've also tried a full adaptation reset.

I live at high elevation (4,000ft) with only 91 octane available (I use Shell, Chevron, Sinclair).

I had the issue happen with the stock intake and now the dinan intake.

What are some other things I could check that could cause a misfire? I did replace the battery and registered it and programmed it. It's a 95 AH battery and I could only choose to program it as a 90 AH.

Finally, the weirdest part is that Paul Johnsons tune has 0 misfires yet the OEM tune has them and so does the 91 ACN tune.

I'm looking for any sort of insight / thoughts. I'm willing to chase down anything reasonable to get this solved. Attached is a stock log with xhp stage 2 I did this morning of a 4th gear pull.

I should note I have no way of knowing if this log has a misfire since BM3 doesn't have the option to log misfires.

https://www.bootmod3.net/log?id=6258...0b43307c4fa812

Edit: Maybe some of you have this happening too and you don't even know it since, like I said you can't tell its even happening unless you constantly monitor for misfires using Bimmerlink. I'd be curious to know if anyone else has this or if my poor baby is just dying slowly.

I've had a somewhat similar/pretty similar issue.
What it potentially could be is there might be a crack or bend somewhere in the cylinder head. But that's worst case but will cause similar issue.

Some things you could do before tearing it down and see. Forgive me if I mention something you already did.
Change coils/spark plugs
Check compression on those cylinders
Check injectors to see if any are stuck open
Check dme to see if there's some short dealing with that particular injector.

But given what you described I'm betting it's something bent or cracked in the head that isn't big enough to throw a cell for it but is off just enough for it not to run properly.

[IMS-340C]

I thought you said it happens only with PJ tune.

I have a misfire when idling the engine between 1500-2000 RPM and was able to log it, from the log I can see all the messed up parameters but I am not sure what initiated it.

[WrxToBeamerGuy]

Originally Posted by IMS-340C

I thought you said it happens only with PJ tune.

I have a misfire when idling the engine between 1500-2000 RPM and was able to log it, from the log I can see all the messed up parameters but I am not sure what initiated it.

no lol that's the only one it doesn't happen on.

[IMS-340C]

No, he said he has a tune that never misfires.

In your case did you find a bend or a crack ?

Originally Posted by Sensational

But given what you described I'm betting it's something bent or cracked in the head that isn't big enough to throw a cell for it but is off just enough for it not to run properly.

[Sensational]

Originally Posted by IMS-340C

No, he said he has a tune that never misfires.

In your case did you find a bend or a crack ?

In my case I had a crack on the ledge with a few bent bolts
But regardless it's pretty weird for it to be fine a custom tune but misfire on everything else. Like even if you do a WOT pull on the custom does it not misfire at all/have really loud backfires?

[WrxToBeamerGuy]

Originally Posted by Sensational

In my case I had a crack on the ledge with a few bent bolts
But regardless it's pretty weird for it to be fine a custom tune but misfire on everything else. Like even if you do a WOT pull on the custom does it not misfire at all/have really loud backfires?

No not at all. The misfires don't happen during pulls just mostly while slowing down / cruising / idling.

Edit: I should note that if it was what you suggested then the misfire would show only on those cylinders rather than being random.

[Sensational]

Originally Posted by WrxToBeamerGuy

No not at all. The misfires don't happen during pulls just mostly while slowing down / cruising / idling.

Edit: I should note that if it was what you suggested then the misfire would show only on those cylinders rather than being random.

Potentially, but it to me is sounding more and more like something around the head or cam. If you can do it take it apart and check or even like disconnecting the valvetronic crankhub and seeing if the car starts up and run fine.

In my instance my car would misfire on startup/while I wasn't actually applying pressure to the throttle. Regular driving it wouldn't misfire but as soon as you release the throttle you could tell something was off and then the eventual misfire. Mine was not random but it would sometimes pop up in two cylinders sometimes not.

[WrxToBeamerGuy]

Originally Posted by Sensational

Potentially, but it to me is sounding more and more like something around the head or cam. If you can do it take it apart and check or even like disconnecting the valvetronic crankhub and seeing if the car starts up and run fine.

In my instance my car would misfire on startup/while I wasn't actually applying pressure to the throttle. Regular driving it wouldn't misfire but as soon as you release the throttle you could tell something was off and then the eventual misfire. Mine was not random but it would sometimes pop up in two cylinders sometimes not.

How many misfire counters did you get?

[Sensational]

Originally Posted by WrxToBeamerGuy

How many misfire counters did you get?

No real clue, I'd only used mhd and a ob2 reader to check codes and I'd only really look once a cel was thrown.
But in my case you could definitely feel when it was about to misfire and the rough idle.

[IMS-340C]

I have a feeling it's a fueling issue, check this log I took for my misfire you can see rail pressure required drops.

https://datazap.me/u/ims/ims-idle?lo...-19&zoom=36-64

[B58]

Did you ever have leaking injectors or stuck open injectors or you just replaced them to help determine if it was the cause to the misfire?

[WrxToBeamerGuy]

Originally Posted by B58

Did you ever have leaking injectors or stuck open injectors or you just replaced them to help determine if it was the cause to the misfire?

I just replaced them because I was at 68k miles and am about to run ethanol with a Pure850. I didn't do it because of the misfires but I was hoping it would get rid of them.

[lietus94]

Did you turn off "cold start" function on OTS tunes? Or turned on GTS start up roar?

[B58]

It might not be a bad idea to do a compression and leak down test. I know this is something we all don't want to do believe me I had to replace my engine due to scored up cylinder walls causing misfire and such, but it's not a bad idea just to rule out the internal of the engine. My compression checked out fine I think it was like 185 across all 6 cylinders, but my leak down test failed and you can hear it leaking.

[WrxToBeamerGuy]

Originally Posted by lietus94

Did you turn off "cold start" function on OTS tunes? Or turned on GTS start up roar?

It's all set to OEM.

[WrxToBeamerGuy]

Originally Posted by B58

It might not be a bad idea to do a compression and leak down test. I know this is something we all don't want to do believe me I had to replace my engine due to scored up cylinder walls causing misfire and such, but it's not a bad idea just to rule out the internal of the engine. My compression checked out fine I think it was like 185 across all 6 cylinders, but my leak down test failed and you can hear it leaking.

Yeah I'm thinking I should do that for piece of mind. Thanks.

[lietus94]

Originally Posted by WrxToBeamerGuy

It's all set to OEM.

Ok. I see this thread is very technical, only threw those in because GTS roar caused misfires for 2 people I know in idle.