[AndyW]

Originally Posted by tealslug

I have an appt. with the dealer later this week - is there any information specific to the ECU upgrade that you can share so that I may have the most amount of details to pass on? Version numbers, detailed description of work done, job codes, etc? Things I can use to speak in terms the service writer / tech might understand?

Andy.

I am on a business trip and don't have access to the receipt with the info. All I requested was an update of all ECU's to current revs and to also reload any ECU's with a current rev. HTH.

[tealslug]

Car is with dealer. Shop foreman could not reproduce the behavior on a short drive (no surprise, really - never had good luck with this). His engine fix suggestions were injectors and/or valve cover - which I told him had just been done (<5k miles ago). I pointed to these threads as anecdotal evidence that ECU update, etc. might be worthwhile.

They are now updating the ECU, which hadn't been done since 2010. As of 3pm PDT yesterday, it had about 6h left to go (is it really that slow?).

Will update here after I've got the car back.

[cwarren]

As of now with just ken doing the module factory reset my car is back to normal
This was an on going issue that could not be fixed by replacing mechanical parts . I highly suggest if your having this surging issue and the maintenance on your car is up to date do the reset first . i spent to much time and money beating my head against the wall trying to figure out what the hell was going on took ken maybe 20 min and all is good

[tealslug]

The ECU reprogram seems to have returned my car to normal, WRT buck 'n surge. That behavior seems to be gone now (yay). My commute has returned to me just being pissed at other drivers, and not my car :-)

[Jklad]

Originally Posted by cwarren

As of now with just ken doing the module factory reset my car is back to normal
This was an on going issue that could not be fixed by replacing mechanical parts . I highly suggest if your having this surging issue and the maintenance on your car is up to date do the reset first . i spent to much time and money beating my head against the wall trying to figure out what the hell was going on took ken maybe 20 min and all is good

Can you share how the reset was done - what was required? I Need to try this...

[Modmike]

My car had the new HPFP and injector change in 2011 and in the last 6 months I:

1) Changed the cam position sensor
2) Replaced plugs and coils
3) Changed Vanos
4) Replaced water pump and thermostat
5) Replaced oil housing seals
6) Rebuilt the Mechatronic with all new solenoids and sonnax kit

The last part I just did because of rough and odd shifts.

The weird surging or stumbling at 1500 RPM started after I did the water pump and thermostat last month. Seeing as I still had the problem after the transmission mechatronic rebuild, I did the reset, multiple times, to no avail. Every reset made the issue almost disappear, only to come back within a day.

I decided to clean the MAP sensor (vacuum not T-MAP which is for boost pressure) and when I pulled it, it was covered in oil and carbon. I used MAP cleaning spray, re-installed, and went for a drive. What a difference! I forgot what smooth power felt like!

I still have a bit of an issue so I ordered a new one that I am waiting on. I am not saying that this is everyones problem, but the symptoms are classic MAP sensor issues, especially high fuel consumption.

Try cleaning yours first to see if it improves your issues, if it does, then replace it.

[Rory]

My car has recently started surging at low - med throttle when driving from a cold start, it goes away after say 1 minute of driving usually.

I flashed back to stage 0 mhd with no difference, I might try uninstalling mhd to check.

Going to change my vacuum lines soon anyway so that might help, think I might also give the MAP sensor a quick clean.

[DaZuc]

I had this exact issue, when I flash MHD and used their stock maps.

When I flashed back to the JB4 BEF it didn't have the issue.

[Modmike]

So the new MAP sensor dramatically improved fuel mileage to the tune of about 3L/100kms! Idle and engine smoothness also massively improved.

Unfortunately all the resets in the world did nothing. Goes away and gradually creeps back. Even the MHD stage 1 flash did nothing.

I just checked and updated every DME that needed it. My MDS80 needed a huge update and 2 other modules as well. By the way this is also a known issue in the M3 that was solved with an update to MSD80.

Will update after testing.

[Varjo]

Very interested to hear updates here. I've been unhappy with MHD stage 1 and 1+ tunes despite logs looking good and recent walnut blast and plugs (no coils or injectors yet, but no indications of an issue). Getting roughness and choppiness around town. Resetting adaptations seems to help for a (short) while and going to stage 0 helps quite a bit.

[jwebb335xi]

Originally Posted by Rory

My car has recently started surging at low - med throttle when driving from a cold start, it goes away after say 1 minute of driving usually.

I flashed back to stage 0 mhd with no difference, I might try uninstalling mhd to check.

Going to change my vacuum lines soon anyway so that might help, think I might also give the MAP sensor a quick clean.

Check all options carefully when flashing. Do not use the O2 option unless you know exactly why you're doing it. Your AFRs will go wild.


Have you logged manuallly while car is acting up? Perhaps those data will help diagnose..

[Modmike]

Using MHD and every update available. Still no luck. The hotter it gets, the worse it is.

[thormessiah]

Can I ask what was used to reset the engine adaptations? I’ve been having this issue for a while now and it’s driving me crazy. Only happens around 2-2.8k rpms coasting, or very light throttle, feels like someone is rhythmically pushing the car from behind. No codes, all maintenance up to date

[Spyro235]

Just want to pipe in- I had this issue. If I remember correctly, the main thing that fixed my pulsing at cruise was replacing one of my O2 sensors. It hadnt thrown any codes, and even during logs, it didn't seem like it was reading wrong. I can pull up old logs if anyone wants to see them to see if out issues were the same. My issue was pretty much only at very light throttle, crusing, and then when it progressed it would stumble as I came to a stop, and the car actually stalled on me twice when I pushed the clutch in to come to a stop.

[thormessiah]

Originally Posted by Spyro235

Just want to pipe in- I had this issue. If I remember correctly, the main thing that fixed my pulsing at cruise was replacing one of my O2 sensors. It hadnt thrown any codes, and even during logs, it didn't seem like it was reading wrong. I can pull up old logs if anyone wants to see them to see if out issues were the same. My issue was pretty much only at very light throttle, crusing, and then when it progressed it would stumble as I came to a stop, and the car actually stalled on me twice when I pushed the clutch in to come to a stop.

Which ones did you replace? Pre-cat or post?

[Spyro235]

Originally Posted by thormessiah

Which ones did you replace? Pre-cat or post?

It ended up being a pre cat one that wasn't throwing a code, and logged fine, but replacing it fixed the issue. Resetting my 02 adaptations from MHD always made the problem WAY better so I figured it was an 02 issue.

[riczon.335i]

Flashed the new mhd v9 beta map and noticed I have been getting this hesitation, stalling effect can be felt every time I use cruise control...So I went a head and replaced both of my pre cat O2 sensors since I already have 130k on the clock. Car ran fine for a few day's and now it keeps throwing me 29E0/29E1 fault codes. I can post an log of me cruise controlling at 65mph when I get off work (graveyard)..I can feel the car bucking, hesitating like strong wind's are hitting the car etc. Hopefully someone can chime in. I'm also on original injector's btw.

[Devildog0905]

Originally Posted by riczon.335i

Flashed the new mhd v9 beta map and noticed I have been getting this hesitation, stalling effect can be felt every time I use cruise control...So I went a head and replaced both of my pre cat O2 sensors since I already have 130k on the clock. Car ran fine for a few day's and now it keeps throwing me 29E0/29E1 fault codes. I can post an log of me cruise controlling at 65mph when I get off work (graveyard)..I can feel the car bucking, hesitating like strong wind's are hitting the car etc. Hopefully someone can chime in. I'm also on original injector's btw.

I'm having a same problem. I've changed spark plugs, injectors, all four o2 sensors, valve cover gasket, and pcv. Still happening. I was on MHD stage 2+. I just put my jb4 on with a back end flash, and reset adaptations again. I'm curious to see what happens. But I'm lost, this issue is driving me nuts

[WoodE30]

I'm getting same issue, under very very light throttle car hesitates/surges. I was going to reset adaptations and maybe reflash my MDH.

[riczon.335i]

Originally Posted by Devildog0905

I'm having a same problem. I've changed spark plugs, injectors, all four o2 sensors, valve cover gasket, and pcv. Still happening. I was on MHD stage 2+. I just put my jb4 on with a back end flash, and reset adaptations again. I'm curious to see what happens. But I'm lost, this issue is driving me nuts

Oddly my issue is gone knock on wood, I reverted back to my custom tune and so far the past few days I'm not getting the hesitation and bogging anymore. I'll stick with my custom plus it has the 1M throttle tables.