[rkmm3]

Hey guys im having a problem with my 08 e90 335i A/T with JB4.

When in M2 and flooring the gas, the car will started to misfire sounds like a AK47, then when i come to a slow it just burbles like its cammed, 2 mins after its back to normal and the SES is off.

2F6C exhaust fumeflap, input signal
29CE misfiring cyl 2

The car was supposedly serviced in nov '11 but the spark plugs were not changed, i have ~45k miles on it now.

Any suggestions please?

[mrbillytalent]

Change spark plugs.

Problem solved. Plugs should be replaced every ~15k on a tuned motor

[rkmm3]

Originally Posted by mrbillytalent

Change spark plugs.

Problem solved. Plugs should be replaced every ~15k on a tuned motor

thank you.

Will do. Do you happen to know which specific plugs.

[GAM]

Originally Posted by rkmm3

thank you.

Will do. Do you happen to know which specific plugs.

Change all of them, then it can be a coil problem, or injector. Also make sure you have the decoupling element on the injector for cylinder 2.

First of all change all the plugs, then if the misfire is still there, check the decoupling element on injector 2, make sure it is there. If the misfire is still there, replace coil 2, then replace injector 2 as the last thing. You can also swap coil/injector from another cylinder and see if the misfire follows.

Get the plugs from Terry on N54tech, if it does solve you problem pm me, I got coils for $30 and injectors for $60 from another member.

Good luck, let us know when you find your problem

[Gugs]

It's never the plugs. Always the coil packs. Newbs. Plugs will give you shit idle, hesitation and random misfires.
Coils just "go" under high load and return to normal after the code clears.
Even with auto clear on.

Simple free way to find out-

Swap coil pack from 1 to 2.
Beat on car and watch the misfire code Jump to 1.

Order coil pack-
Problem solved.

Welcome.

[LuSt4Boost]

Originally Posted by Gugs

It's never the plugs. Always the coil packs. Newbs. Plugs will give you shit idle, hesitation and random misfires.
Coils just "go" under high load and return to normal after the code clears.
Even with auto clear on.

Simple free way to find out-

Swap coil pack from 1 to 2.
Beat on car and watch the misfire code Jump to 1.

Order coil pack-
Problem solved.

Welcome.

Not true...

A few months ago, my car would ONLY misfire and throw codes under high load. Seemed to idle smooth and drove perfect when not getting into it. Changed the plugs and drove perfect. Haven't had a misfire or code since changing them.

[rkmm3]

Originally Posted by Gfabry

Change all of them, then it can be a coil problem, or injector. Also make sure you have the decoupling element on the injector for cylinder 2.

First of all change all the plugs, then if the misfire is still there, check the decoupling element on injector 2, make sure it is there. If the misfire is still there, replace coil 2, then replace injector 2 as the last thing. You can also swap coil/injector from another cylinder and see if the misfire follows.

Get the plugs from Terry on N54tech, if it does solve you problem pm me, I got coils for $30 and injectors for $60 from another member.

Good luck, let us know when you find your problem

thanks for your help....start with plugs since they're due anyways.

Originally Posted by Gugs

It's never the plugs. Always the coil packs. Newbs. Plugs will give you shit idle, hesitation and random misfires.
Coils just "go" under high load and return to normal after the code clears.
Even with auto clear on.

Simple free way to find out-

Swap coil pack from 1 to 2.
Beat on car and watch the misfire code Jump to 1.

Order coil pack-
Problem solved.

Welcome.

thanks bud, i need to do the plugs anyways, i'll start with them. if not coils it is.

Originally Posted by LuSt4Boost

Not true...

A few months ago, my car would ONLY misfire and throw codes under high load. Seemed to idle smooth and drove perfect when not getting into it. Changed the plugs and drove perfect. Haven't had a misfire or code since changing them.

thanks, glad to know you fixed your issue and it was with plugs.

I will follow up after i change the plugs!

[onejapman]

so what is the update i just installed mine and same thing is happening

[SctsOut06]

I'm having similar issues. DCI with JB4 running map1. It happened this morning on the interstate going about 65. Floored it up to 80 got SES light and car shudders around 2k-3k. Drove for a mile or so to pull off the road and light went off. Was able to pull extremely hard with no issues. After leaving work and approximately 60 miles later same thing happened on the interstate. Drove car appx 2 miles home and the light was still on but the car was driving fine. No shuddering and seemed to pull hard. I'm not loosing any boost. Car has 43k on it.

[SctsOut06]

Just to update my situation...and this may help the OP--replaced the ignition coil on cylinder #2 and it solved all my problems. Could not get the car to replicate what it was doing. Bought a set of spark plugs, now I just have to wait until the spark plug tool comes in to change them.

Conducted my first experiment with mixing E85 with 91 today and running map 5. It wasn't a huge gain like I anticipated but it may take a few more cycles for the ECU to completely adapt.

[enrita]

Missfire is always plugs, coils or injectors. You just need to find the right cause.