[BmwFanFL]

Hello --

UPDATE - See post #12 - Still seeing timing issues after plugs - logs attached in post 12. - thoughts please?

I've been using my Cobb for a few weeks now. I am in the Palm Beach Florida area, running 93 octane with only the Stage 1 Sport maps v301. I have no other mods on the car. I'm the only owner of this 2008 AT which has roughly 25K miles and was only recently modded. It's had all scheduled maintenance but oil changes around 6-7000 miles each. The VIN is, well, you don't need that...

In the first week, I took some logs and would see timing correction up to 4 degrees, usually on just one cylinder at a time, once on two. These were short WOT periods with decent cool downs of a few minutes in between. In spite of that, the car felt strong and consistent. Typical Florida weather for this time of year, low 80s at peak.

In the last week, twice I felt a strong momentary pause during hard acceleration, almost like the break was slammed very briefly, then it recovered power within, I guess, 1/2 second. I wasn't logging at the time or staring at the dashboard, but in the 35 to 45 MPH range. I don't think it was related to a shift, but am not certain. Possibly traction control, but that usually occurs at lower speeds and has always felt more like restraint or holding back, not an outright pause.

I logged a few quick WOT periods over the weekend. These all show more correction events than before, a little more correction (say 5 or 6), and in one case 4 or 5 cylinders at once in one case. I didn't catch one of the hesitation/pause events in a log though.

No codes were captured since installation.

It seems I likely have weak plugs, coils, injectors, or something else. I plan to have the plugs replaced first. Does this seem reasonable or is another course recommended?

Separately, is a typical tire/service center qualified to change plugs on this car -- if so, it would be very convenient. Otherwise, can anyone recommend a good BMW independent service center in the West Palm Beach, FL area (I'm somewhat North of there).

Thanks for any thoughts. I'm sure I'll get this worked out quickly.

[ATP]

Why not swap the plugs yourself?

[oshusttoley]

below is the top list of things to look for after tuning. All of the items below have an accelerated life span when you tune your car meaning you will have to look out for or change more often

-Spark plugs
-Coilpacks
-Injectors
-High Pressure/Low Pressure Fuel Pump
-Carbon Build up in intake valves
-Vanos Solenoid

[rader1]

Swap the plugs yourself. It's easy and way cheaper to buy the tools and plugs than to pay a shop to do it. I think there are a few guys local to you who may be able to help if you need it. But it's super easy to do.
Here's a DIY: http://www.1addicts.com/forums/showthread.php?t=602804

[MidwestGolfBum]

Given that you are running the 301 maps, that could be the somewhat common pause that a lot of people talk about as well. They seem to have made things much better with the 400 and 401 beta maps, though some have had a few issues with them.

What others have said are all correct as well.

[marv85]

Start by swapping the plugs. It made a lot of difference on my car. You can either follow the link rader posted or the video posted by COBB on misfire debug in which they detail changing plugs/coils.

[Jeff@TopGearSolutions]

Originally Posted by ecjohnston

Given that you are running the 301 maps, that could be the somewhat common pause that a lot of people talk about as well. They seem to have made things much better with the 400 and 401 beta maps, though some have had a few issues with them.

What others have said are all correct as well.

I would update first. Then look into the plugs.

[enrita]

Originally Posted by Jeff@topgearsolutions

I would update first. Then look into the plugs.

^ this

[crypticc]

Traction control fully off?

[BmwFanFL]

The plugs have been replaced. The old ones were definitely worn substantially, but not too seriously (only 25K). I'm glad to have new ones in -- I went with BMW branded plugs.

It seems a little smoother and stronger after the change, but not enough time behind the wheel to draw conclusions, as it was intermittent before. The car may also need a little adaptation time.

I'll drive and log over the next few days and post what I find. Thanks for the suggestions.

[marv85]

Originally Posted by BmwFanFL

The plugs have been replaced. The old ones were definitely worn substantially, but not too seriously (only 25K). I'm glad to have new ones in -- I went with BMW branded plugs.

It seems a little smoother and stronger after the change, but not enough time behind the wheel to draw conclusions, as it was intermittent before. The car may also need a little adaptation time.

I'll drive and log over the next few days and post what I find. Thanks for the suggestions.

I was getting timing drops across the board around when my plugs got to~45k. When I changed them, I logged literally the first run and had no timing drops on a more aggressive map.

log

[BmwFanFL]

The only runs I did are short bursts from stop or near stop (e.g., after turning).

Well, the plugs (and new oem air filter) made it feel smoother, but still seeing multiple cylinders correcting. I have virtual dyno, but it doesn't seem to number the scales, so I just attached a couple of csvs (as txt).

I did get 3 short runs - not attached - without any timing correction. I had a few of those before as well, but the ratio of clean/timing pull runs may be a little better now.

This is on v301 Sport, no other mods, 93 octane Shell, sea level, high 70s.

If its coils, it would have to be several of them. It seems more likely that its something else, given so many cylinders get involved.

Any thoughts/comments/recommendations would be appreciated.

[BmwFanFL]

One Zasquatch graph capture here - log #6

[marv85]

It would be easier to read if you would plot the actual timing on all cylinders vs Timing correction. Plus the only timing we can see above is for cylinder 1 and the timing drop is not huge.

Why is your IAT so high? you almost reached 140! IATs can also cause timing drops

[AU335i]

your timing drops aren't too bad as marv85 stated. Have you done a ECU reset? Doing a full reset might help after you changed plugs.


also, not sure, but your lambda(afr) seems to fluctuate alot more than I'm use to seeing on my graphs. Is this a 3rd gear pull?

[BmwFanFL]

Update:

I updated AP Manager, the firmware, and then map to 401 LT Aggressive earlier tonight. I also reset the ECU adaptations, in case changing maps doesn't do that.

I did a few light pulls then some quick runs with logs (short bursts) with logging enabled. They look somewhat better, AFR 12-14 and more stable, some +/- 2 to 3 degrees of timing for brief periods, usually cyl 4 to 6 together. However, 4 out of 6 brief logs had no timing discrepancies I noticed. Also, aggressive is a stronger mapping (I assume), so less timing pulls suggests to me that its working better.

I'll get a few cleaner runs in the next couple days, after its adapted, and post the results. It's definitely improved, hopefully enough. We were at 85 degrees ambient, so it isn't ideal... It probably needs a liquid coolant based inter-cooler ;-)


Thanks for suggestions and feedback so far. I want the car to run perfectly, but even with the car considerations, I still think this tune is absolutely professional. The ease of management and straightforward logging are very cool. I think Cobb should add a reporting/graphing/log submission (to Cobb) tool into AP Manager. Of course, they have nothing else to do with their time......