[KaiserN54]

2007 e90 335i 6MT here. Only mods are a procede and DCI's.

I have been having this problem for a long time. I have gone through two sets of turbos, new actuators, new injectors and LFPF, LFPF sensor, walnut blasted intake manifold, etc.

The car runs great most of the time. I am not getting any codes or limp modes, etc.

The problem is hard to describe, but I'll do the best job I can of explaining it:

When I drop into 4th gear @ 60mph, I expect a certain amount of "pull" or acceleration to 80mph, which i recognize as being "normal" for the car. But every once in a while, if I drop into 4th (at the same RPM, flat surface, same speed, etc) it can feel like the car is plugged up. 100hp seems to just be missing. I will get the power back for maybe 500 RPMs, only to have it fall back on its face.

Getting off the gas and re-punching it will sometimes solve the problem, even if I leave it in gear. I sometimes notice this when doing quick 2-3, or 3-4 shifts, as well.

I am guessing maybe a vacuum line issues, spark plugs (they were changed last summer though), or maybe VANOS solenoids? I would attach some logs but don't have any at the moment capturing the phenomena.

Does anyone have any experience with this kind of issue?

[Jeff@TopGearSolutions]

Have you tried re-uploading software and firmware, or even a new version? Logs would definitely help even if its not of the problem, a 3rd gear log can likely tell us something, especially if you go from 3rd Gear WOT into 4th.

BTW which PROcede specifically?

[KaiserN54]

Originally Posted by Jeff@TopGearSolutions

Have you tried re-uploading software and firmware, or even a new version? Logs would definitely help even if its not of the problem, a 3rd gear log can likely tell us something, especially if you go from 3rd Gear WOT into 4th.

BTW which PROcede specifically?

v5. I am using the most recent non E85 maps. I have already tried reflashing/re-uploading. I will trying logging again at my earliest opportunity which is Wednesday. Of course I sent logs to vishnu last week: no response, despite my calling them about it.

[marv85]

I'm pretty sure the problem will be obvious if you log... make sure to include all the necessary channels (boost and timing should be there)

[joec500]

Could be a long shot, but I had a throttlebody go bad and experienced some similar issues, but I also had throttle potentionmeter errors codes as well.

[enrita]

try out another tune and see if you have the same issue. Also try uninstall it completely and see how it runs stock boost.

[OpenFlash]

Originally Posted by KaiserN54

2007 e90 335i 6MT here. Only mods are a procede and DCI's.

I have been having this problem for a long time. I have gone through two sets of turbos, new actuators, new injectors and LFPF, LFPF sensor, walnut blasted intake manifold, etc.

The car runs great most of the time. I am not getting any codes or limp modes, etc.

The problem is hard to describe, but I'll do the best job I can of explaining it:

When I drop into 4th gear @ 60mph, I expect a certain amount of "pull" or acceleration to 80mph, which i recognize as being "normal" for the car. But every once in a while, if I drop into 4th (at the same RPM, flat surface, same speed, etc) it can feel like the car is plugged up. 100hp seems to just be missing. I will get the power back for maybe 500 RPMs, only to have it fall back on its face.

Getting off the gas and re-punching it will sometimes solve the problem, even if I leave it in gear. I sometimes notice this when doing quick 2-3, or 3-4 shifts, as well.

I am guessing maybe a vacuum line issues, spark plugs (they were changed last summer though), or maybe VANOS solenoids? I would attach some logs but don't have any at the moment capturing the phenomena.

Does anyone have any experience with this kind of issue?

Easiest way to troubleshoot, as others have said, is to just capture this issue in a datalog. By the sounds of it, it's hardware related since its intermittent. If I had to be place a bit, i'd stay its a sticking waste gate that is preventing boost build up from time to time. That's the only way I can think of where you would feel such a sudden loss power power at full throttle. Either way, a datalog will prove (or disprove) this theory. Just make sure you log:

Boost
Boost Setpoint
CAN actual ignition advance
CAN DBW Throttle
CAN Actual AFR bank1/2
CAN Fuel Trim bank 1/2

That's it..
Cheers,
shiv

[KaiserN54]

Originally Posted by shiv@vishnu

Easiest way to troubleshoot, as others have said, is to just capture this issue in a datalog. By the sounds of it, it's hardware related since its intermittent. If I had to be place a bit, i'd stay its a sticking waste gate that is preventing boost build up from time to time. That's the only way I can think of where you would feel such a sudden loss power power at full throttle. Either way, a datalog will prove (or disprove) this theory. Just make sure you log:

Boost
Boost Setpoint
CAN actual ignition advance
CAN DBW Throttle
CAN Actual AFR bank1/2
CAN Fuel Trim bank 1/2

That's it..
Cheers,
shiv

Shiv,

I sent several datalogs to Robert last week but haven't heard back. Admittedly not all of those variables were captured. One thing I noticed though is that I seem to be hitting fuel trims of 30 despite just running stage one on 93 octane. (ohio gasoline)

[KaiserN54]

Originally Posted by shiv@vishnu

Easiest way to troubleshoot, as others have said, is to just capture this issue in a datalog. By the sounds of it, it's hardware related since its intermittent. If I had to be place a bit, i'd stay its a sticking waste gate that is preventing boost build up from time to time. That's the only way I can think of where you would feel such a sudden loss power power at full throttle. Either way, a datalog will prove (or disprove) this theory. Just make sure you log:

Boost
Boost Setpoint
CAN actual ignition advance
CAN DBW Throttle
CAN Actual AFR bank1/2
CAN Fuel Trim bank 1/2

That's it..
Cheers,
shiv

Okay, here are some datalogs, 3-4th gear runs, as you asked. How do they look? Definitely doesn't feel right.





log1.txt




log2.txt



log3.txt

[KaiserN54]

Hello? Anyone?

[OpenFlash]

I think I'm responding to you via email. You're looks look completely unremarkable. Boost is fine. Fuel trims are fine. Throttle blade is wide open. Even ignition advance (when i plotted it) look fine. I emailed you some more suggestions on what else you can log. But so far, everything looks, well...fine.

[quasitime]

Symptoms sound exactly like my car before I randomly found the thread on vacuum leaks.

At this point I've had at least 2 sections of vacuum tube that were coming apart, and 2 more that were on their way out.

Quick test is popping off that cap immediately after turning off the car.

http://www.e90post.com/forums/showthread.php?t=546560

[KaiserN54]

Originally Posted by quasitime

Symptoms sound exactly like my car before I randomly found the thread on vacuum leaks.

At this point I've had at least 2 sections of vacuum tube that were coming apart, and 2 more that were on their way out.

Quick test is popping off that cap immediately after turning off the car.

http://www.e90post.com/forums/showthread.php?t=546560

After reading through the thread, I have to say alot of people seemed to have been having the same issues as me...so I am feeling optimistic that checking these lines will lead to a fix. The lag/lack of power is only some of the time, can vary in intensity, and isn't significant enough to throw codes. I can make peak boost, but the car doesn't always feel like it does so everytime, and it often comes on sort of roughly, like an on/off switch. I haven't always been super gental when putting on my DCI's, charge pipe, etc. I will check them out.