[xjackhunter]

I have an 08 335i N54 and have experienced some issues recently. I've had a misfire under load since I bought the car a couple months ago. As of right now, the car is 100% stock except for an MHD flash *misfire was present before the flash*. I have replaced all of the coils and spark plugs so far. Until today, I was convinced that my issue was bad injectors but the car has been acting even weirder recently so I've decided to share my symptoms and hope someone can give me some advice.

- hard misfire under load
- rough idle
- long crank
- fuel smell during cold starts

The car is still drivable, but I cannot beat on it at all, and have to drive it like a '99 Corolla.

Any help would be great, thanks!

[rjahl]

Originally Posted by xjackhunter

I have an 08 335i N54 and have experienced some issues recently. I've had a misfire under load since I bought the car a couple months ago. As of right now, the car is 100% stock except for an MHD flash *misfire was present before the flash*. I have replaced all of the coils and spark plugs so far. Until today, I was convinced that my issue was bad injectors but the car has been acting even weirder recently so I've decided to share my symptoms and hope someone can give me some advice.

- hard misfire under load
- rough idle
- long crank
- fuel smell during cold starts

The car is still drivable, but I cannot beat on it at all, and have to drive it like a '99 Corolla.

Any help would be great, thanks!

Probably injectors,

Pull your plugs and smell for gasoline.

[xjackhunter]

Originally Posted by rjahl

Probably injectors,

Pull your plugs and smell for gasoline.

I'll do that tomorrow afternoon and update.

[IllSic_Design]

When I had issues and my hpfp went out I had long cranks, sometimes rough idle, and when I would go into boost at all it would start cutting out and bucking all over the place. I also had misfire,cylinder cutoff codes, and some fuel pump codes.

[jokers_greg]

Long cranks are usually a good indicator of hpfp

[monoid]

Probably injectors, because of the fuel smell on cold start.

Logs or do you just prefer to keep guessing?

[xjackhunter]

Originally Posted by FCobra94

Logs or do you just prefer to keep guessing?

I'm confused as to how a log will determine anything other than a misfire...

Originally Posted by xjackhunter

I'm confused as to how a log will determine anything other than a misfire...

Now is a good time to learn up:
https://www.e90post.com/forums/showthread.php?t=1269588

[xjackhunter]

Originally Posted by FCobra94

Now is a good time to learn up:
https://www.e90post.com/forums/showthread.php?t=1269588

Damn I had no idea you could log with MHD. Guess I'll give it a try later tonight.

[xjackhunter]

Originally Posted by FCobra94

Now is a good time to learn up:
https://www.e90post.com/forums/showthread.php?t=1269588

https://datazap.me/u/xjackhunter/bmw...8;data=3-12-22

- hope this is useful

Originally Posted by xjackhunter

https://datazap.me/u/xjackhunter/bmw...0&data=3-12-22

- hope this is useful

Unfortunately not...

Datalog a single gear run, at wide open throttle in 3rd gear, from ~2500rpm to redline (or as high as your are willing to take it)....then completely let off the the throttle for at least 3 or 4 seconds while still in gear.

Post the results.

[xjackhunter]

Originally Posted by FCobra94

Unfortunately not...

Datalog a single gear run, at wide open throttle, from ~2500rpm to redline (or as high as your are willing to take it) in 3rd gear....then completely let off the the throttle for at least 3 or 4 seconds while still in gear.

Damnit. Expect another link in about an hour.

[xjackhunter]

Originally Posted by xjackhunter

Damnit. Expect another link in about an hour.

Also, does the pull have to be in third? I don't think I can go to redline in third without being arrested for super speeding....

[xjackhunter]

Originally Posted by xjackhunter

Also, does the pull have to be in third? I don't think I can go to redline in third without being arrested for super speeding....

Originally Posted by xjackhunter

Also, does the pull have to be in third? I don't think I can go to redline in third without being arrested for super speeding....

Pls reply ASAP. I'm currently sitting in a QT parking lot wondering if I'm going to have to risk my freedom in order to figure out if my hpfp is dying lol.

[xjackhunter]

3rd gear was a no go...
1st gear pull:
https://datazap.me/u/xjackhunter/bmw...&data=3-22
2nd gear pull:
https://datazap.me/u/xjackhunter/bmw...&data=3-22

Hope these help.

Those logs are worthless.

At least your injectors don't seem to be leaking on decel.

[xjackhunter]

Originally Posted by FCobra94

Those logs are worthless.

At least your injectors don't seem to be leaking on decel.

Oof. Any insight as to why they're useless? - I have 0 experience with data logging.

[RnmEvo9]

Originally Posted by xjackhunter

Oof. Any insight as to why they're useless? - I have 0 experience with data logging.

It has to be done in 3rd gear when the car is under more load. How hard is it to find an open road with no traffic after you have scoped it out for cops?

[xjackhunter]

Originally Posted by RnmEvo9

It has to be done in 3rd gear when the car is under more load. How hard is it to find an open road with no traffic after you have scoped it out for cops?

Very hard in my area atleast. Only a couple of backroads in the area, none long enough to get a pull in. Guess I'll have to go on the highway for this one.

[type-dRew]

Originally Posted by xjackhunter

Very hard in my area atleast. Only a couple of backroads in the area, none long enough to get a pull in. Guess I'll have to go on the highway for this one.

Yeah I wouldn't recommend trying a log on surface streets. I always just pull onto the highway on ramp and if there is traffic I pull to the shoulder and wait. When traffic clears, get up to third gear as quickly as possible with manual mode at a low'ish rpm and make a hit that way(do not press kickdown switch if its enabled). Run it to redline or until it shifts and let it coast for a few off throttle before closing the log.

I also do at least 1 press of DSC to make sure there is no traction control interference.

[xjackhunter]

Do these codes mean anything regarding the injector or hpfp issue?