[JimThot]

i have a 09 335i with an FBO 93 oct stage 2+ ots mhd tune and i had the car sitting through the winter which was about 6 months.

I took it out for a lil 20 min drive last week and i had no codes or issues and then i took it out again a couple days ago for another 30-45 min drive and it was fine untill i did a wot pull and i got the code.

I figured it was just an ignition coil because near the end of the summer it was doing the same thing and it was an ignition coil causing the problem.

Today though, i tried moving the coil around to see if it was the issue and it wasn’t. i then swapped the spark plug around and it still didn’t fix it. i took the injector (index 12) out and it had some buildup on the tip so i cleaned it off and put it back in and it didn’t fix it.

the spark plug hole was clean from any oil and i also checked fuel pressure and on the high pressure side i was getting ≈ 700psi and on the low pressure side i was getting ≈70 psi.

right now, after clearing the code it would run a little rough at idle and then the engine light for the code would come on and then run really rough.

I don’t know what else to check.

[GoRomeo]

Originally Posted by JimThot

i have a 09 335i with an FBO 93 oct stage 2+ ots mhd tune and i had the car sitting through the winter which was about 6 months.

I took it out for a lil 20 min drive last week and i had no codes or issues and then i took it out again a couple days ago for another 30-45 min drive and it was fine untill i did a wot pull and i got the code.

I figured it was just an ignition coil because near the end of the summer it was doing the same thing and it was an ignition coil causing the problem.

Today though, i tried moving the coil around to see if it was the issue and it wasn’t. i then swapped the spark plug around and it still didn’t fix it. i took the injector (index 12) out and it had some buildup on the tip so i cleaned it off and put it back in and it didn’t fix it.

the spark plug hole was clean from any oil and i also checked fuel pressure and on the high pressure side i was getting ≈ 700psi and on the low pressure side i was getting ≈70 psi.

right now, after clearing the code it would run a little rough at idle and then the engine light for the code would come on and then run really rough.

I don’t know what else to check.

Pls post the code you are getting? Any other codes besides the one you keep clearing?

[JimThot]

Originally Posted by GoRomeo

Pls post the code you are getting? Any other codes besides the one you keep clearing?

“29CD Combustion misfires, cylinder 1”

no other codes given

[Sgop335]

Originally Posted by JimThot

“29CD Combustion misfires, cylinder 1”

no other codes given

Looks like plug and coil checks out based on swap.
If cyl 1 code is persistent, look for cyl 1 specific items…which would be fuel injector. Compression is another.
Looks like injector was wiped or something but was not replaced or swapped w known good one and coded.

[GoRomeo]

Originally Posted by JimThot

“29CD Combustion misfires, cylinder 1”

no other codes given

Not familiar with that code. Have you researched it? I'm sure someone is.

Lots of people talk about doing walnut blasting 🤔. Im considering doing it as preventing maintenance. Dirty valves can cause headaches I ve heard. Last time I asked at indy shop they wanted like $800. I'm like WTF? 😄

[JimThot]

Originally Posted by Sgop335

Looks like plug and coil checks out based on swap.
If cyl 1 code is persistent, look for cyl 1 specific items…which would be fuel injector. Compression is another.
Looks like injector was wiped or something but was not replaced or swapped w known good one and coded.

i’m hoping it’s a clogged injector and it just needs cleaning. is there a way to clean them at home or do they need to be professionally cleaned.

[JimThot]

Originally Posted by GoRomeo

Not familiar with that code. Have you researched it? I'm sure someone is.

Lots of people talk about doing walnut blasting 🤔. Im considering doing it as preventing maintenance. Dirty valves can cause headaches I ve heard. Last time I asked at indy shop they wanted like $800. I'm like WTF? 😄

i’ve seen that too but my engine only has around 75k miles so i doubt that it would help a lot. i’m believing it’s a clogged injector

[Sgop335]

Originally Posted by JimThot

i’m hoping it’s a clogged injector and it just needs cleaning. is there a way to clean them at home or do they need to be professionally cleaned.

likely clogged. Fuel injector cleaner but engine has to run, I send mine out for professional cleaning and high pressure testing to a service in Houston, has worked well many times