[BrejL]

I have a 2007 335i (n54)

Recently started having misfires so I changed coils(eldor) and plugs(ngk 2 step colder .022 gap.) no changes.

The weird thing is when I cold start the car it will shake and correct (makes it sound cammed&#128557 for about 5 minutes until it revs itself up to 1200 rpm and then idles smooth… like there are no issues. I can drive all day long off a cold start without turning her off and it runs perfect. The problem comes when engine gets hot, and then is shut off and turned back on. When it’s hot it will have the rough idle again but the misfiring and correcting will continue for the whole drive.
It’s like hit or miss if I’ll get a smooth drive or a jerky misfiring drive if I start it up while hot.

Haven’t seen anyone with this specific problem, I’m not too knowledgeable on this topic but I assume it wouldn’t be injectors since it has the ability to run great and does? If anyone could help me out I’d appreciate it.
Posted 2 MHD logs with cylinder timings, the first is when I started it up while hot and the second is after about 5 minutes when the idle just returns to normal. If anything else is needed to help me out please let me know.

Thanks!

[whyzee125]

How many miles on the car?

Which index of injectors do you have?

Can you post a datazap link to a log?

What are your mods? Unless you're on upgraded turbos, you should be running stock Bosch plugs.

[konstat]

Originally Posted by BrejL

I have a 2007 335i (n54)

Recently started having misfires so I changed coils(eldor) and plugs(ngk 2 step colder .022 gap.) no changes.

The weird thing is when I cold start the car it will shake and correct (makes it sound cammed&#128557 for about 5 minutes until it revs itself up to 1200 rpm and then idles smooth… like there are no issues. I can drive all day long off a cold start without turning her off and it runs perfect. The problem comes when engine gets hot, and then is shut off and turned back on. When it’s hot it will have the rough idle again but the misfiring and correcting will continue for the whole drive.
It’s like hit or miss if I’ll get a smooth drive or a jerky misfiring drive if I start it up while hot.

Haven’t seen anyone with this specific problem, I’m not too knowledgeable on this topic but I assume it wouldn’t be injectors since it has the ability to run great and does? If anyone could help me out I’d appreciate it.
Posted 2 MHD logs with cylinder timings, the first is when I started it up while hot and the second is after about 5 minutes when the idle just returns to normal. If anything else is needed to help me out please let me know.

Thanks!

I agree with whyzee about the plugs. Switch back to Bosch. 1 steps are roughly for 500 to 650 whp and 2 steps for 600+.

It probably injectors but before we go there (because they’re expensive) how dirty is your throttle body? Dirty throttle bodies cause warm start issues on all cars. After you check/clean the throttle body, reset your throttle adaptations and make sure you turn off ignition and wait 30 seconds after.

How about your intake valves when was last walnut shell blast done.

Can you also try running a fuel injector cleaner like BG44K. Make sure you drive the car for about 20 miles straight with fuel injector cleaner in tanks.

Do you also have a copy of INPA to perform a smooth running test. That will pin point which cylinders are causing the misfire.