[Occ224]

2008 bmw 335i 90k miles
I tried swaping iginition coils. that didnt fix the problem.
I tried new spark plugs. That didnt fix the problem.
I'm stuck with maybe a vacuum leak which ive search everywhere or a failing fuel injector? What else could it be?
It drives normal. But when I put power to it, it will randomly stutter while climbing rpms durring a pull. but if I pretty much floor it, it will missfire pretty bad and throw a service engine code. It will ither go away and stop missfireing after a few miles or i turn it off then back on again and its back to normal.
It only missfires with stage 1 tune. It didnt missfire before on the tune.
Im sure it will start missfireing with stock tune after a while. I think the stage 1 tune will make the problem more noticeable quicker.
What is the next step to take to diagnose my problem? Please help thank you so much for any info you may have.

[mweisdorfer]

Originally Posted by Occ224

2008 bmw 335i 90k miles
I tried swaping iginition coils. that didnt fix the problem.
I tried new spark plugs. That didnt fix the problem.
I'm stuck with maybe a vacuum leak which ive search everywhere or a failing fuel injector? What else could it be?
It drives normal. But when I put power to it, it will randomly stutter while climbing rpms durring a pull. but if I pretty much floor it, it will missfire pretty bad and throw a service engine code. It will ither go away and stop missfireing after a few miles or i turn it off then back on again and its back to normal.
It only missfires with stage 1 tune. It didnt missfire before on the tune.
Im sure it will start missfireing with stock tune after a while. I think the stage 1 tune will make the problem more noticeable quicker.
What is the next step to take to diagnose my problem? Please help thank you so much for any info you may have.

You need a code.

MHD can produce the code, if that's what you have.

If not, you need either: Carly, Foxwell/Schwaben scan tool or Ista (rheingold). The best bet would be the Foxwell scan tool, if you are not CPU savy. You can get one on Amazon or ECS tuning.

I would say you probably have a bad fuel injector.

If your coils are original to the car, replace them.

The Foxwell scan tool can code the new injectors to the car.

If your injectors are original to the car, get 6 new ones. Index 12

[GATORB8]

What did plug 6 look like when you took it out? A bad injector will make the plug black, wet, and/or smell like gas.

[Occ224]

Originally Posted by mweisdorfer

You need a code.

MHD can produce the code, if that's what you have.

If not, you need either: Carly, Foxwell/Schwaben scan tool or Ista (rheingold). The best bet would be the Foxwell scan tool, if you are not CPU savy. You can get one on Amazon or ECS tuning.

I would say you probably have a bad fuel injector.

If your coils are original to the car, replace them.

The Foxwell scan tool can code the new injectors to the car.

If your injectors are original to the car, get 6 new ones. Index 12

Thank you for your response.
The code is p0306 if that is what you were asking. I tried replacing the coil but that didnt work. I also tried replacing spark plug but that didnt work. Can I swap cylinder 6 and 5 fuel injectors to see if cylinder 5 will start missfireing?

[Occ224]

Originally Posted by GATORB8

What did plug 6 look like when you took it out? A bad injector will make the plug black, wet, and/or smell like gas.

Plug 6 was pretty black but I have a new one in there and it is still missfireing
Do you think i can swap fuel injectors yo see if i missfire in a diffrent cylinder?

[mweisdorfer]

Originally Posted by Occ224

Plug 6 was pretty black but I have a new one in there and it is still missfireing
Do you think i can swap fuel injectors yo see if i missfire in a diffrent cylinder?

I wouldn't swap fuel injectors. Not a good idea. I don't think it will seal.

[mweisdorfer]

Originally Posted by Occ224

Thank you for your response.
The code is p0306 if that is what you were asking. I tried replacing the coil but that didnt work. I also tried replacing spark plug but that didnt work. Can I swap cylinder 6 and 5 fuel injectors to see if cylinder 5 will start missfireing?

P0306 is a general code. Did you happen to get a BMW specific code?

http://www.n54tech.com/forums/showthread.php?t=44416

Without knowing the specific bmw code, based on the fact that you have new plugs & put in a new coil and are still getting a misfire, and the original plug was black, I'd say the injector is bad. I'm making a educated guess here.

https://m.eeuroparts.com/Parts/14631...A2C9521190280/

This is the best price on the net that know of. I'd buy all 6 and call it good. However, I'd buy a Foxwell scan tool so you can diagnose the problem to be sure that it's an injector issue for sure. This tool can also code the new injectors.

https://www.googleadservices.com/pag...I0Q0Qx6BAgJEAE

[TheMidnightNarwhal]

Originally Posted by mweisdorfer

You need a code.

MHD can produce the code, if that's what you have.

If not, you need either: Carly, Foxwell/Schwaben scan tool or Ista (rheingold). The best bet would be the Foxwell scan tool, if you are not CPU savy. You can get one on Amazon or ECS tuning.

I would say you probably have a bad fuel injector.

If your coils are original to the car, replace them.

The Foxwell scan tool can code the new injectors to the car.

If your injectors are original to the car, get 6 new ones. Index 12

INPA won't be able to give code?

[mweisdorfer]

Originally Posted by TheMidnightNarwhal

INPA won't be able to give code?

Yes it will. You better be tech savvy in order to use INPA and be able to decipher German

[TheMidnightNarwhal]

Originally Posted by mweisdorfer

Yes it will. You better be tech savvy in order to use INPA and be able to decipher German

Oh okok I was wondering.

But my INPA is in english? Unless it's when you open the actual codes notepad that it's all in german?

[mweisdorfer]

Originally Posted by TheMidnightNarwhal

Oh okok I was wondering.

But my INPA is in english? Unless it's when you open the actual codes notepad that it's all in german?

You must have ista version. I like that version.

[TheMidnightNarwhal]

Originally Posted by mweisdorfer

You must have ista version. I like that version.

Oh ok, I'm not even sure what I have. I think I have also SSS and DIS.

I'm only familiar with TIS, don't know for the other stuff.

[mweisdorfer]

Originally Posted by TheMidnightNarwhal

Oh ok, I'm not even sure what I have. I think I have also SSS and DIS.

I'm only familiar with TIS, don't know for the other stuff.

If you can work with programs like ista d & p, that's the way to go, but not everyone is tech savvy.

I'm an Mac user. That sort of works against me as ista is a windows program. I'm not really familiar with windows based programs. I have ista, but I haven't really played with it too much. I haven't had a need knock on wood....

I typically recommend a scanner like Foxwell/ Schwaben for most folks.

[TheMidnightNarwhal]

Originally Posted by mweisdorfer

If you can work with programs like ista d & p, that's the way to go, but not everyone is tech savvy.

I'm an Mac user. That sort of works against me as ista is a windows program. I'm not really familiar with windows based programs. I have ista, but I haven't really played with it too much. I haven't had a need knock on wood....

I typically recommend a scanner like Foxwell/ Schwaben for most folks.

Pretty expensive tho

[mweisdorfer]

Originally Posted by TheMidnightNarwhal

Pretty expensive tho

The scanner or Ista?

You can get ista for free, if you know where to look.

[GATORB8]

A bad injector will black the plug pretty quickly. Once you know that's it, I'd replace as quick as possible, note you can do just the 3 injectors on the bank if necessary.

My bad injector was able to foul out my ignition coil eventually.

[Occ224]

Originally Posted by mweisdorfer

P0306 is a general code. Did you happen to get a BMW specific code?

http://www.n54tech.com/forums/showthread.php?t=44416

Without knowing the specific bmw code, based on the fact that you have new plugs & put in a new coil and are still getting a misfire, and the original plug was black, I'd say the injector is bad. I'm making a educated guess here.

https://m.eeuroparts.com/Parts/14631...A2C9521190280/

This is the best price on the net that know of. I'd buy all 6 and call it good. However, I'd buy a Foxwell scan tool so you can diagnose the problem to be sure that it's an injector issue for sure. This tool can also code the new injectors.

https://www.googleadservices.com/pag...I0Q0Qx6BAgJEAE

My mhd scan tool said 29d2 i believe. It said combustion missfire cylinder 6

[mweisdorfer]

Originally Posted by Occ224

My mhd scan tool said 29d2 i believe. It said combustion missfire cylinder 6

http://www.n54tech.com/forums/showthread.php?t=41057

Looks like injectors.......

[TheMidnightNarwhal]

Originally Posted by mweisdorfer

The scanner or Ista?

You can get ista for free, if you know where to look.

The Foxwell/Shwaben stuff

I only paid 20$ for the cable and was able to find the software

I can't wait to test out the other software, seems like some pretty nice tools.

[Occ224]

Originally Posted by mweisdorfer

http://www.n54tech.com/forums/showthread.php?t=41057

Looks like injectors.......

Will i need to buy a cuppler for the the injector you said for me to buy? The metal piece that goes around it about half way and spins. And what about the small black o ring? Does the injector come with both?

[mweisdorfer]

Originally Posted by Occ224

Will i need to buy a cuppler for the the injector you said for me to buy? The metal piece that goes around it about half way and spins. And what about the small black o ring? Does the injector come with both?

Typically speaking, you must buy the coupler by itself. I wouldn't just buy 1 injector. I mean if you have to from a financial standpoint I get it. However, the 1 injector you have a problem with is a tell tale sign of things to come regarding the other 5.

Tunes are very hard on turbos, injectors, plugs & coils.

[Occ224]

Originally Posted by mweisdorfer

Typically speaking, you must buy the coupler by itself. I wouldn't just buy 1 injector. I mean if you have to from a financial standpoint I get it. However, the 1 injector you have a problem with is a tell tale sign of things to come regarding the other 5.

Tunes are very hard on turbos, injectors, plugs & coils.

Hey man so i replaced injector and put the flow rate in and it ran amazing for a good 20 miles then I got on the gas and it started missfireing in cylinder 6 again the problem went away a few miles of driving it calm but I'm sure it would come back again. Please help haha