[trapahh]

I have two issues with my car that I cant seem to find the solution. 2010 335i, FBO MHD.
I had my car in storage for about a year due to being overseas. When I came back, I knew I needed to get work done on it so I got the following done. Fluids change, replaced spark plugs and had them gapped appropriately, new throttle body, and lastly a new stage 2 fuel pump from BMS.
When I got the car back, the car had MHD v7 And whenever I smash the car, I would misfire terribly. The codes presented via tablet was cylinder 3 and 4. So I took it to another shop closer to my house and they checked to see if the spark plugs were gapped correct(they were), some test on the injectors which turned out fine so I though why not just change the two coils for 3 and 4. So I told them fine, change it. I got a call from the mechanic and he told me I was misfiring but this time it was 3 and 6. I tried to then change the tune from V7 to v8. Still misfiring when I WOT. Changed it from v8 to v9(wasn’t in the states when v9 dropped so I was hoping it would fix it), nothing happen. I even reset all adaptations and still, the same problem would occur. I said fuck it and just when to stock. Whenever I WOT, no problems what so ever.
Another issue that I had noticed was whenever I fill my gas tank, it would not go past half way. I didn’t realize it the first time I filled up and when I did notice it, I figured it would even out over time. Like a little calibration thing since I haven’t driving the car for a quite some time. If I put half a tank of gas in the car when it’s close, the needle will move maybe 25% but when I drive it would settle in the middle. I just don’t get it. I’m not that knowledgeable when it come to problems like this.
I know this is a long post and I do apologize but I’m trying to give as much information as possible to try and find a solution to these problems. Lately people have been pulling on me and I can’t do much in a stock vehicle. But no seriously, anything will help!

[SixSix]

Sounds like it might be fueling issue, what's your LPFP reading at as well as your rail pressure at idle and during a pull. When you flash a different map it requires more fuel to compensate for the extra boost so it could be possible that one of your pumps is strong enough to have it run stock just fine, but when it demands more fuel with the tune it's unable to keep up. AFAIK any N54 car manufactured after around 2009 has the MSD81 DME which doesn't have the mosfet failing issue that the MSD80 DMEs had. Mosfets are what supply the voltage to the coils and injectors I believe. I would start by checking your fueling system. Otherwise replace the other 4 coils if everything looks good on the fueling end. Do you have a KDCAN cable or do you flash with the WIFI adapter?

[trapahh]

So the only code that I get via tablet MHD is
29FE - Fuel low pressure sensor, electric

The thing is, I’ve always had that code, and for years without a problem. Is it possible to just change that sensor? What will I need to buy and is it a big/costly job?

I am also using a KDCAN cable

[Saif2018]

Originally Posted by trapahh

So the only code that I get via tablet MHD is
29FE - Fuel low pressure sensor, electric

The thing is, I’ve always had that code, and for years without a problem. Is it possible to just change that sensor? What will I need to buy and is it a big/costly job?

I am also using a KDCAN cable

Logs?

Make sure HPFP and LPFP are logged.

[SixSix]

I agree with Saif2018, if you can grab a log with mhd that replicates the misfire that would be extremely helpful to finding out why it's misfiring. I would also suggest getting INPA for PC and running diagnostics through there. MHD and any other scanning tool are likely to "Dummy" the codes to make them easier to understand. INPA allows you to read all the live data as well as the true codes. I don't think it's related to the sensor if you've had that code for a while and it's been fine but you never know.

[trapahh]

Sorry I took so long to respond and I hope you guys don't mind helping still. https://datazap.me/u/deebro180/log-1...log=0&data=3-8

So today when I was driving ( Car FBO still but still stock via MHD tune) my car went into limp mode and felt very shaky. I then pulled over and restarted the car. The code didn't come back after that but the codes present via tablet was
29CF - DME; Combustion Misfires, Cylinder 3
29DC - DME; Clyinder injector cutout
29F3- DME: Fuel low-pressure sensor, electric (I have had this code for a while now when it was tune and was able to WOT fine)
2AAF- DME: Fuel Pump, plausibility

Do you think this has anything to do with my initial problem? (fuel gauge problems and misfiring when WOT)

[Saif2018]

Originally Posted by trapahh

Sorry I took so long to respond and I hope you guys don't mind helping still. https://datazap.me/u/deebro180/log-1...log=0&data=3-8

So today when I was driving ( Car FBO still but still stock via MHD tune) my car went into limp mode and felt very shaky. I then pulled over and restarted the car. The code didn't come back after that but the codes present via tablet was
29CF - DME; Combustion Misfires, Cylinder 3
29DC - DME; Clyinder injector cutout
29F3- DME: Fuel low-pressure sensor, electric (I have had this code for a while now when it was tune and was able to WOT fine)
2AAF- DME: Fuel Pump, plausibility

Do you think this has anything to do with my initial problem? (fuel gauge problems and misfiring when WOT)

You need to do a proper log, most of the logging options are missing

Make sure the following options are at least logged,

Cylinder timing (1-6)

Timing cyl 1

Fuel low pressure sensor

Lambda Bank 1 and 2

Rail pressure

WGDC

STFT and LTFT

IAT

[trapahh]

My bad, I will upload a few with the correct parameters. Though I will say that every time I tried to capture a log, it would freeze on the tablet so hopefully the logs that I have provided is suffice
https://datazap.me/u/deebro180/log-1...11-12-19-30-31

https://datazap.me/u/deebro180/log-1...og=0&data=3-19

[Dave92N54]

Originally Posted by trapahh

My bad, I will upload a few with the correct parameters. Though I will say that every time I tried to capture a log, it would freeze on the tablet so hopefully the logs that I have provided is suffice
https://datazap.me/u/deebro180/log-1...11-12-19-30-31

https://datazap.me/u/deebro180/log-1...&data=3-19

I'm on mobile right now so datazap is kind of annoying but in both logs your lpfp reading is much higher than i've seen. Mine is usually around 82psi and I know even that is on the high end, yours reads 90+. Honestly i'd give the lpfp sensor a go, not too hard and not too expensive of a job, but i'm wondering if that's just your stage2 pump and a stock tune. You have lots of timing corrections though, is your gas old by any chance? What fuel are you using? Since your rail pressure looks fine the only thing other than the sensor I could imagine causing an issue like this would be the fpr (if not poor fuel)

[Saif2018]

Originally Posted by trapahh

My bad, I will upload a few with the correct parameters. Though I will say that every time I tried to capture a log, it would freeze on the tablet so hopefully the logs that I have provided is suffice
https://datazap.me/u/deebro180/log-1...11-12-19-30-31

https://datazap.me/u/deebro180/log-1...og=0&data=3-19

Not sure if the shop you took it too did this,

If you haven't sorted the misfire out yet, start with swapping plugs/coils from cylinder 3, recheck codes, if misfires follows, then you know its a plug/injector that's causing it. If it doesn't then the next thing to check is injectors by swapping the one from the cylinder it's misfiring, remember to change seals.

As Dave92N54 said, your LPFP seema to be stuck at 90+psi, this could be because the sensor is faulty.

Exactly which map from V7, 8 or 9 were you running, when you took the log?