[tello2020]

hello
I have a 2007 bmw 335i have a 4 fault code.

29cd misfire cylinder 1

29cf misfire cylinder 3

29ce misfire cylinder 2

29cc misfire several cylinder

I have changed

spark plugs ignition coils swap injectors,

new oxygen sensor

change mosfets in the DME

some one help please.



Thanks

[relative4]

Smoke test, walnut blast

[tello2020]

Originally Posted by relative4

Smoke test, walnut blast

smoke test ok
remove intake clean all the valves.

[mweisdorfer]

Originally Posted by tello2020

smoke test ok
remove intake clean all the valves.

When the mosfets go, they can fry the injectors & coils.

Sometimes the mosfets aren't soldered in correctly and can cause problems.

If you know that the new mosfets are soldered in correctly & your coils & injectors are good 100%, then you probably need to do ms 80 to ms 81 DME upgrade.

[tello2020]

Originally Posted by mweisdorfer

When the mosfets go, they can fry the injectors & coils.

Sometimes the mosfets aren't soldered in correctly and can cause problems.

If you know that the new mosfets are soldered in correctly & your coils & injectors are good 100%, then you probably need to do ms 80 to ms 81 DME upgrade.

I send the dme to a place that repairs computers they told me the computer was fine but they recommended to upgrade the mosfets and they did
Plug everything back but still misfiring cylinders 1 2 3

[mweisdorfer]

Originally Posted by tello2020

I send the dme to a place that repairs computers they told me the computer was fine but they recommended to upgrade the mosfets and they did
Plug everything back but still misfiring cylinders 1 2 3

Then it's probably your coils or injectors. Maybe both.

I'd move the coils around to see if you can get the code to love to a different cylinder. If not, then it's your injectors

How do your plugs look? From what I've read those could be effected too.

You can always upgrade to an MS 81. That's a gamble if it will solve your problem. Less expensive than 6 new injectors though.

You are sort of in an expensive pickle! 😌

[tello2020]

I did swap coils and Injectors
From bank 1 to bank 2
But don’t change the code still misfiring
cylinder 1 2 3 new spark plugs and the DME it’s update with new mosfets
I don’t think is the DME it's something else but can’t find it

[tello2020]

Originally Posted by mweisdorfer

Then it's probably your coils or injectors. Maybe both.

I'd move the coils around to see if you can get the code to love to a different cylinder. If not, then it's your injectors

How do your plugs look? From what I've read those could be effected too.

You can always upgrade to an MS 81. That's a gamble if it will solve your problem. Less expensive than 6 new injectors though.

You are sort of in an expensive pickle! 😌

I did swap coils and Injectors
From bank 1 to bank 2
But don’t change the code still misfiring
cylinder 1 2 3 new spark plugs and the DME it’s update with new mosfets
I don’t think is the DME it's something else but can’t find it

[Warishuku]

Hey man, have you already checked the harness integrity for the bank 1 components? Check the connectors for coils and injectors with a multimeter in order to check if they are getting voltage.
Also, I don't know if those have a fuse or a relay or something that maybe is messed up, it could be worthy to check that route too.

[tello2020]

Originally Posted by Warishuku

Hey man, have you already checked the harness integrity for the bank 1 components? Check the connectors for coils and injectors with a multimeter in order to check if they are getting voltage.
Also, I don't know if those have a fuse or a relay or something that maybe is messed up, it could be worthy to check that route too.

good point I will check that to make sure coils and injectors have a good voltage. thank you,

[mweisdorfer]

Originally Posted by tello2020

I did swap coils and Injectors
From bank 1 to bank 2
But don’t change the code still misfiring
cylinder 1 2 3 new spark plugs and the DME it’s update with new mosfets
I don’t think is the DME it's something else but can’t find it

Check the grounds on the coils

[tello2020]

Hello everyone, I am still stuck with my misfiring problem anyone solved a problem similar than mine ?

[Red_Bean_Bun]

Do a compression test ...

[tello2020]

Hi
compression test all cylinders ok

[Red_Bean_Bun]

Originally Posted by tello2020

Hi
compression test all cylinders ok

Then leak down test is next ...

[tello2020]

Originally Posted by Red_Bean_Bun

Then leak down test is next ...

this is what i have changed so far
Spark plugs
Coils
Injectors
02 sensors
Map sensor
Remove intake to clean valves
2 front catalytic converters
Smoke test ok no air leaks
Sended DME to replace the mosfets
Misfiring still the same
Cylinder 1 2 3

[vncung]

Have you personally check the mosfets to make sure they did it right?

[mweisdorfer]

Originally Posted by tello2020

this is what i have changed so far
Spark plugs
Coils
Injectors
02 sensors
Maf sensor
Remove intake to clean valves
2 front catalytic converters
Smoke test ok no air leaks
Sended DME to replace the mosfets
Misfiring still the same
Cylinder 1 2 3

I don't think they fixed the mosfets correctly.

Either that or perhaps you have to upgrade the DME to an MSD81.

The mosfets you have now are FDB 14N30??

[Red_Bean_Bun]

Originally Posted by tello2020

this is what i have changed so far
Spark plugs
Coils
Injectors
02 sensors
Maf sensor
Remove intake to clean valves
2 front catalytic converters
Smoke test ok no air leaks
Sended DME to replace the mosfets
Misfiring still the same
Cylinder 1 2 3

There’s no MAF sensor in a N54.

The leak down test is ok - no valve issues ?

Any 30bb codes ?

[tello2020]

Originally Posted by Red_Bean_Bun

There’s no MAF sensor in a N54.

The leak down test is ok - no valve issues ?

Any 30bb codes ?

I meant Map sensor
No valve issues
No 300bb codes
Only misfiring codes
Cylinder 1 2 3

[tello2020]

Originally Posted by vncung

Have you personally check the mosfets to make sure they did it right?

Yes check mosfets they are ok

[tello2020]

Originally Posted by mweisdorfer

I don't think they fixed the mosfets correctly.

Either that or perhaps you have to upgrade the DME to an MSD81.

The mosfets you have now are FDB 14N30??

open the dme check the mosfets they are ok FDB 14N30