[torrque]

Originally Posted by Nexus313

If that doesn't work, I think I found something new..

if you watch this video, you'll see that when he disconnects his low pressure fuel pump wires, his car still starts but will stall after a little bit.

I know your car probably doesnt stall this quick, but it's worth getting the wiring harness on the fuel pump looked at aswell.

Thanks; I had a look and checked, unplugged and re-plugged all connectors. They look fine, and pump is new... Been changed by previous owner as he had fuel pressure errors. Problem is I have zero codes stored on the DME, nada. It does trigger codes when I unplug stuff and test, so it's monitoring Ok. We'll see what BMW says next week, and take it from there. Also, the DME behaves OK, I flashed it twice now, has not missed a beat ever.

[Nexus313]

Originally Posted by torrque

Thanks; I had a look and checked, unplugged and re-plugged all connectors. They look fine, and pump is new... Been changed by previous owner as he had fuel pressure errors. Problem is I have zero codes stored on the DME, nada. It does trigger codes when I unplug stuff and test, so it's monitoring Ok. We'll see what BMW says next week, and take it from there. Also, the DME behaves OK, I flashed it twice now, has not missed a beat ever.

you know.. there's more connectors under the pump itself when you de-assemble it? He could have not done the DIY correctly.. (assuming he did a DIY) .. it's easy to mess stuff like that up.

[torrque]

Originally Posted by Nexus313

you know.. there's more connectors under the pump itself when you de-assemble it? He could have not done the DIY correctly.. (assuming he did a DIY) .. it's easy to mess stuff like that up.

I suppose I can take it all out and check when I get it back if not fixed (car is at BMW now for investigation) ... It was done by a specialist shop in BMW's so in theory it should be fine. I also have solid low pressure rail over 60PSI all the time, especially now after the low pressure sensor change.

[Nexus313]

Originally Posted by torrque

I suppose I can take it all out and check when I get it back if not fixed (car is at BMW now for investigation) ... It was done by a specialist shop in BMW's so in theory it should be fine. I also have solid low pressure rail over 60PSI all the time, especially now after the low pressure sensor change.

Hmm your fuel pressure does fluctuate right? A solid pressure that never changes or barely does and just flat lines at all time does mean a bad pressure sensor.

but I'm guessing yours is fine since you changed it.. goodluck with the BMW investigation.. hopefully they finally find it!

PS: just a side note, even "specialist shops" can mess up sometimes

[torrque]

Originally Posted by Nexus313

Hmm your fuel pressure does fluctuate right? A solid pressure that never changes or barely does and just flat lines at all time does mean a bad pressure sensor.

but I'm guessing yours is fine since you changed it.. goodluck with the BMW investigation.. hopefully they finally find it!

PS: just a side note, even "specialist shops" can mess up sometimes

Yes, pressure is fluctuating nicely now, but at least 5PSI higher than before... I don't think I have a fueling issue, no errors of any kind, both pumps and sensors new... I mean this car has everything but the fuel lines and wiring old, everything else spark and fuel wise has been changed

I am tempted to believe it's the wiring harness to injectors... From docs I have from previous work done at other shop, it started when they changed fuel injectors. Could have damaged the harness as I saw some missing insulation on a couple of injector wiring. If they don't find the problem, my next step is to try a new harness.

[n54Nazar]

i had same issue with my 07 335xi
it would randomly drop all gauges and buck. it was the positive cable connection to the fuse box

[MJ80.]

Yep my guages would also bounce like absolute mad. This was with a piggyback fitted, once that was pulled problem solved. It will be wiring somwhere.

[torrque]

Yeah, my problem is only rpm needle drops, and it bucks. All other gauges stay still. German Performance suspected the crank angle sensor (that is where the rpm info comes from) , and they replaced it, together with complete wiring all the way to DME... same difference.
Car is now for over a week at Herb Chambers BMW in Boston; I am not raising my hopes up, those guys are way too busy to spend some time to track this fault. I am sure they'll give up also soon and call me in to pick it up as is. I have a loaner in the form of a brand new 320i automatic, horrible car. If this is the new bmw, I don't want it.

[Nexus313]

Originally Posted by torrque

Yeah, my problem is only rpm needle drops, and it bucks. All other gauges stay still. German Performance suspected the crank angle sensor (that is where the rpm info comes from) , and they replaced it, together with complete wiring all the way to DME... same difference.
Car is now for over a week at Herb Chambers BMW in Boston; I am not raising my hopes up, those guys are way too busy to spend some time to track this fault. I am sure they'll give up also soon and call me in to pick it up as is. I have a loaner in the form of a brand new 320i automatic, horrible car. If this is the new bmw, I don't want it.

At least you got a rental for a week I don't think they can give up.. I mean can they?

[torrque]

Originally Posted by Nexus313

At least you got a rental for a week I don't think they can give up.. I mean can they?

I don't know, time will tell I suppose. I called and left a message for the service advisor who took my car in to call me back for an update; no callbacks. I am pretty confident they have no clue what to do with it... I am sure someone will soon inquire "where is that new white loaner 320i we have" , oh shoot, it's been with that guy for over 2 weeks now

[torrque]

BMW of America officially gave up chasing my fault; they said they would need to start from scratch and remove all parts that have been changed and replace whatever it needs replacing... I knew they won't fix it without an error code, they have no clue where to look.

Now back to investigation. I have a few ideas, will post back.

[crossface007]

honestly your best bet at this point would be to get an OBDII scanner and take a look at all your parameters. I.e fuel trims, throttle position, fuel rail pressure, o2 sensors, Maf sensor reading just to get started.

[Nexus313]

Originally Posted by torrque

BMW of America officially gave up chasing my fault; they said they would need to start from scratch and remove all parts that have been changed and replace whatever it needs replacing... I knew they won't fix it without an error code, they have no clue where to look.

Now back to investigation. I have a few ideas, will post back.

Have you got on the phone with BMW NA and tried to escalate this matter (outside of your stealership?

Man that really sucks.

[MysticRob]

I reread this thread and keep thinking it's likely an electrical issue related to the DME, or DME itself.
That lack of codes must be overcome, otherwise you'll just continue to throw parts at it.

OP:
Any open recalls?
What exactly are ALL your mods? First post indicated BOVs in use, not stock DVs.
If not a battery terminal and/or cabling issue, then maybe it's something still DME related. I keep coming back to the lack of ANY codes whatsoever. Your supposedly new DME may still be a problem. Try a brand new OEM DME programmed by the dealership, and ensure they upgrade all subsystem modules simultaneously. Start from scratch and see if the lack of codes and/or drivability problems persist.

[torrque]

Originally Posted by crossface007

honestly your best bet at this point would be to get an OBDII scanner and take a look at all your parameters. I.e fuel trims, throttle position, fuel rail pressure, o2 sensors, Maf sensor reading just to get started.

I have, if you look in the other MHD thread, I monitored the life of it... Nothing unusual. All fuel trims are fine, O2 sensors voltages are fine, HPFP and LPFP pressures are fine, just the occasional drop of rpm and stutter (which now has become so bad it's almost undriveable; it also killed it completely once, had to restart).

[torrque]

Originally Posted by MysticRob

I reread this thread and keep thinking it's likely an electrical issue related to the DME, or DME itself.
That lack of codes must be overcome, otherwise you'll just continue to throw parts at it.

OP:
Any open recalls?
What exactly are ALL your mods? First post indicated BOVs in use, not stock DVs.
If not a battery terminal and/or cabling issue, then maybe it's something still DME related. I keep coming back to the lack of ANY codes whatsoever. Your supposedly new DME may still be a problem. Try a brand new OEM DME programmed by the dealership, and ensure they upgrade all subsystem modules simultaneously. Start from scratch and see if the lack of codes and/or drivability problems persist.

I have zero mods, not sure where I posted about BOV, but car is completely stock, including the software.

Dme has been reprogrammed, and on first drive, has behaved EXACTLY the same; throwing money on another DME is 99% a waste. It's also an MSD81, and it will generate the proper codes as I unplug stuff for testing (for example, I unplugged everything off fuse F11, which is shared by the DME with various components, looking for a wiring or electrical fault on one of those) . I eliminated all shared electrical components on that common voltage rail, including all injectors as being a fault.
I took it to BMW and they did the airbag recall, and inspected the blower heater, and it's all good (they have no parts for that recall yet). Other than that, everything has been changed on the car in the past 9 months :

Injectors
plugs
coil packs
alternator
battery
carbon clean done
throttle body
High pressure and low pressure pumps (high pressure BMW recall done)
Low pressure AND high pressure sensors
Crank angle sensor swapped twice, and new wiring from it to DME (this was the main suspect for a while, and I am still not 100% on this, will open it up again).
Brand new main ground strap ran additional to the existing one (BMW oem strap)

@MysticRob: You are right, the lack of codes is what is throwing off every mechanic investigating it. Problem is, being an electrical issue or consumption, it trips the voltage to the DME also, and it is unable to log any error, being dropped itself I believe. I have a 2-3V voltage drop every time the stutter happens, hence my theory...Changed the main DME relay for this issue, no luck, the same. Spent hours opening up the junction box and wiring , looks new, and it has the recall done (it has a screw in there, not a clamp at the back).

Many thanks

[MysticRob]

Originally Posted by torrque

I have zero mods, not sure where I posted about BOV, but car is completely stock, including the software.

I figured BOVs from your first post in your thread, below -- just sounded odd considering you said it's stock:

Originally Posted by torrque

...I am suspecting throttle body, as I revved it a couple of times on the spot, and when the problem occurred I heard the blow off valves going off, so throttle body closing although I was accelerating...

Originally Posted by torrque

Dme has been reprogrammed, and on first drive, has behaved EXACTLY the same; throwing money on another DME is 99% a waste. It's also an MSD81, and it will generate the proper codes as I unplug stuff for testing (for example, I unplugged everything off fuse F11, which is shared by the DME with various components, looking for a wiring or electrical fault on one of those) . I eliminated all shared electrical components on that common voltage rail, including all injectors as being a fault.

But it's still the same DME you've had problems with the entire time, so whatever programming or troubleshooting you're doing may not be diagnosing anything. Whatever fault MIGHT actually lie in the current DME may not be readily observable by your troubleshooting thus far. Start from scratch and ensure that whatever DME you used to replace the first one isn't also bad. Was the DME purchased new from BMW? If not, I'd already be wondering WHY it was even for sale.

[musa]

Originally Posted by MysticRob

I figured BOVs from your first post in your thread, below -- just sounded odd considering you said it's stock:





But it's still the same DME you've had problems with the entire time, so whatever programming or troubleshooting you're doing may not be diagnosing anything. Whatever fault MIGHT actually lie in the current DME may not be readily observable by your troubleshooting thus far. Start from scratch and ensure that whatever DME you used to replace the first one isn't also bad. Was the DME purchased new from BMW? If not, I'd already be wondering WHY it was even for sale.

I would bet $100 this issue will be fixed with a new DME ... why? Because I've been through a somewhat similar issue - everything and anything replaced except the DME while chasing a crazy violent limp mode issue when the car gets warm. Almost got rid of the car. One Russian master tech at a stealership quietly tipped me to just replace the DME with a brand new one. All the problems vanished to this day. Cost was a sum of $2,099.85 (brand new DME $1,470.75 + DME cooling fan $141.60 + coding new DME and installation labor $487.50). Purchase and work was done at Crevier BMW Santa Ana, CA. It was the last thing remaining to be replaced other than the engine. I figured this was better than replacing the engine or getting rid of the car (with practically new parts) and getting into car payments for a replacement vehicle.

[torrque]

Originally Posted by MysticRob

I figured BOVs from your first post in your thread, below -- just sounded odd considering you said it's stock:





But it's still the same DME you've had problems with the entire time, so whatever programming or troubleshooting you're doing may not be diagnosing anything. Whatever fault MIGHT actually lie in the current DME may not be readily observable by your troubleshooting thus far. Start from scratch and ensure that whatever DME you used to replace the first one isn't also bad. Was the DME purchased new from BMW? If not, I'd already be wondering WHY it was even for sale.

Sorry, my bad, I was not clear in my statement. I bought another DME, an MSD81, which has replaced the OEM MSD80 in the car. The DME came from a crashed 2009 535i, which I bought on Ebay from a BMW wrecker. Spoke to him on the phone. The guy who programmed the DME was from N54tech, and he is very respected there. He did all tests he could on it and said it would not give me trouble, and that DME is as good as it gets. After I changed it, obviously had to reset all codes to avoid limp mode, and it started right up. But the bucking/shaking was identical as when the original DME was running...
What is the chance that the second DME has the same problem as the first one, and not logging any fault codes either (just like the first one)? 1% , 0.01%, I don't know. But they are very slim, don't you agree ?

If the DME is the problem, hopefully the bloody thing would just die and not start on me, but it starts and runs well... until it doesn't...

Many thanks

[buster84]

Originally Posted by torrque

Sorry, my bad, I was not clear in my statement. I bought another DME, an MSD81, which has replaced the OEM MSD80 in the car. The DME came from a crashed 2009 535i, which I bought on Ebay from a BMW wrecker. Spoke to him on the phone. The guy who programmed the DME was from N54tech, and he is very respected there. He did all tests he could on it and said it would not give me trouble, and that DME is as good as it gets. After I changed it, obviously had to reset all codes to avoid limp mode, and it started right up. But the bucking/shaking was identical as when the original DME was running...
What is the chance that the second DME has the same problem as the first one, and not logging any fault codes either (just like the first one)? 1% , 0.01%, I don't know. But they are very slim, don't you agree ?

If the DME is the problem, hopefully the bloody thing would just die and not start on me, but it starts and runs well... until it doesn't...

Many thanks

I didn't read the whole thread just page 1 and last one sincre you listed all the parts you replaced. My first question, are you running the stock flash? Have you tried installing a new positive and negative cable? Maybe check the battery wiring from the battery to the engine bay/alternator as well as the engine ground?

Based on what I've read it's either a bad dme, bad wiring (maybe a rat got in the car and ate wiring to stay alive), or maybe you got a bad injector. Strange enough I had a similar issue on my e93 and it turned out to be a leaking injector that was only noticeably leaking while driving and not at idle so they replaced all the injectors under warranty, and new plugs and it was gone. I also wasnt throwong any codes. So maybe you got a defective injector even if it was new. Just something to recheck.

Also of you never programmed the car and your just assuming the original tune is installed based on what the previous owner sent you id have the tune file looked at to be sure. It's possible the guy backed up a modified tune and labeled it original and didn't save the real original because he thought that he already did. This is Just another area to inpect considering bmw failed to help.

Edit: if you didn't already get it, you should find a copy of rheingold and use it with a dcan cable and diagnose it better. Other apps tend to not show hidden shadow codes that only rheingold can do.

[torrque]

Originally Posted by buster84

I didn't read the whole thread just page 1 and last one sincre you listed all the parts you replaced. My first question, are you running the stock flash? Have you tried installing a new positive and negative cable? Maybe check the battery wiring from the battery to the engine bay/alternator as well as the engine ground?

Based on what I've read it's either a bad dme, bad wiring (maybe a rat got in the car and ate wiring to stay alive), or maybe you got a bad injector. Strange enough I had a similar issue on my e93 and it turned out to be a leaking injector that was only noticeably leaking while driving and not at idle so they replaced all the injectors under warranty, and new plugs and it was gone. I also wasnt throwong any codes. So maybe you got a defective injector even if it was new. Just something to recheck.

Also of you never programmed the car and your just assuming the original tune is installed based on what the previous owner sent you id have the tune file looked at to be sure. It's possible the guy backed up a modified tune and labeled it original and didn't save the real original because he thought that he already did. This is Just another area to inpect considering bmw failed to help.

Edit: if you didn't already get it, you should find a copy of rheingold and use it with a dcan cable and diagnose it better. Other apps tend to not show hidden shadow codes that only rheingold can do.

Thanks for you suggestions. I have Rheingold, and scanned it completely with it... all modules are green, show no problems.

I also tried stage 1 from MHD and it is the same (more pronounced bucking as it obviously boosts more). I have a brand new OEM ground to the chassis, and all battery cables and Junction box have been checked; no signs of overheating or spark or anything like that... I have eliminated the injectors as being a problem by removing the injector and coil pack connector; ran like that in 5 cylinders one by one ; the stuttering is exactly the same, no difference with any of the injectors removed.

I also eliminated the DME as I said by replacing it... It is the stock tune that came with it for a N54. What I have not eliminated, is the wiring harness from the engine bay, the one connecting all sensors, injectors and coils to the DME. A couple of injectors had stray wires exposed (when I bought the car) , somebody really abused it when working on the engine. I have insulated those wires (cut, solder, shrink wrap) now, but I am thinking of buying a new wiring harness soon.
Many thanks.

[torrque]

The other thing I have not looked at, is valve conditions. I saw an invoice from previous owner for carbon cleaning about 2000 miles ago, but what if it has not been done? Can anyone confirm how it behaves with stuffed/ dirty valves, is a stuttering possible, or more of a performance problem?