[Pr335bob]

hi!
2007 335i e92 sport pack no oil cooler. competely stock except for cobb.

Ive had my cobb for about 3-4 months, after reading countless reviews decided to go with ease of install over JB4.

Problem is i keep getting misfire on cyl 3 all the time. Ive swapped the igntion coil, after that replaced the sparkplug. Same code thrown.

I removed the cobb tune from the car today and no codes thrown. Ive been driving the whole day car is smooth!!!!! Smoother than with the cobb.
when i WOT on cobb stage 1 or 1 aggresive it would stutter and sometimes misfire. On stg 0 it wouldnt stutter as much but wasnt as smooth as stock.

Any idea whats causing this? Has this happened to any of you fellow cobb users? How about the Jb4 crowd has this happened to you?

I want to figure this out before i start modding. plans are
1. Oil Cooler
2. FMIC
3. LSD
4. maybe just maybe meth if i get bored.

back story:
figuring this out could be the deciding factor between me keeping the car or going 2010+ sti or 2009+ evox.

after a lot of thinking and research, i believe my best option is to spend about 3-4k over time on perf upgrades on the 335i rather then get a new debt. I live in Puerto Rico and the tax for these cars is ridiculous. 2010 sti (37-40k used) Evo 2009 (29-33k used). The 335 is almost paid for and im thinking about getting more performance out of it and make it a car that suits my needs. (some track use, some drag, daily driving) all for fun.
But i want a reliable car i hope the 335i proves to be this car.

[bmw287]

Having the same problem with mine in cylinder 1.... I was told my high pressure fuel pump could be going.

[Pr335bob]

wow i heard the extended the warranty on the hpfp. look that up!
also if it doesnt appear when stock bmw will not honor it i assume we are in a bad position. Ever try the Jb4? I read in one case that after the person spent money and time changin sparks and coils, it ended up being a fuel injector. Thing is that was just one case i read. Dont want to spend money if maybe someone firgured something else out. he also switched to Jb4 so idk

[bmw287]

Nope never tried jb4

[Pr335bob]

http://www.e90post.com/forums/showthread.php?t=631829

[Pr335bob]

a lot of ppl have had this prob
apparently and differ fixes.

this kind of sucks cause we can not isolate the problem.

[bmw287]

It's weird because I put the stage 1 back on and it drives fine

[gtaccord]

Get a carbon cleaning. If it is not that then you have a bad injector.

[Pr335bob]

did u do anything differ?

[Pr335bob]

carbon cleaning DIY type thing or a mechanic?

[Pr335bob]

did u dop anything differ to the car?

[bmw287]

Nope all I did was get gas and put the tune on, so I'm going to drive it until it happens again and then I'll start to check out things..... So try to install it again and see what happens

[vasillalov]

Prepare for injector number 3 to completely fail soon. It's not Cobb at all!

[Pr335bob]

Vasillalov
Personal experience?

[enrita]

Exactly lol us not cobb but something not right in your engine. Probably injector.

[Kayani_1]

My first year with both JB4 and then switching to Cobb stg. 1 agg. I never had an issue. Then all of sudden I was having misfires on Cobb stg. 1 Agg 93 oct.

I got all my spark plugs changed and the car has been running like brand new as if it never had misfires.

So it is not Cobb but either your injector are bad or spark plugs get them changed. Also, getting your valves cleaned and HPFP service done can't hurt. I hope your octane level for gas is also good.

[ErvGotti]

Agree with Vasillalov, I had the same problem as you where it wouldn't misfire stock but would with the tune Cobb tune on. For me it was the Injectors actually three to be in fact but only number 3 was throwing the misfire code. I took it to the dealer and they replaced the plugs and coils at first but didn't solve the issue. Then they checked injector pressures and found three to be out of spec with cylinder 3 being the worst. They replaced them and haven't had a problem since.

[Pr335bob]

Thanks everyone for the help! I'm going to try to switch the fuel injector. Now are they're any issues or different injector numbers I should look out for? I'm thinking just order one and have it coded to see if its that. If it is then Ill replace the other 5.

[badass335]

Since you have cobb, try logging fuel pressure. I have procede and was getting misfire on cyl1 all of a sudden. Changed plugs, moved coil and still cyl 1. Checked out my fuel trims and running a bit lean. That was causing misfire. Checked out lpfp requested vs actual values and big difference. Changed lpfp and no more misfires.

I should mention, stock I had no misfires. Also, my case, I noticed the idle would be solid at 650rpm then after a minute or 2, it would give a stutter and then raise up to 800rpm.

[Pr335bob]

well in myc casethe car cold starts are fine but after ir kind of settles down to 600rpm it shakes a little until you drive it . then its normal

[Pr335bob]

ive checked the injectors 1-6 are all 261-07 versions are these good? or an older version?

[DanielGonz]

Sounds like an injector issue.. hmm.