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mikstew mikstew is offline
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Default JB4 going lean under WOT - Logs attached - 08-04-2019, 02:33 PM

Hi all,

I installed the JB4 a month or so ago (into a 2008 135i with 45k miles, bone stock), and noticed if I go WOT for any longer than a few seconds, the car kicks into limp mode, the CEL comes on, and I get misfire codes.

So I bought the log cable and did a 3rd gear WOT run. I only got up to about 3500 RPM before limp mode kicked in. I attach the log.

I've reviewed other people's logs and I cannot immediately see why this is happening on my car.

Can someone review these logs and let me know?

Thanks,
Mike
Attached Files
File Type: csv 190804_1413 3rd gr limp mode.csv (11.6 KB, 28 views)

Last edited by mikstew; 08-04-2019 at 02:39 PM..
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Default 08-04-2019, 03:58 PM

Quote:
Originally Posted by mikstew
Hi all,

I installed the JB4 a month or so ago (into a 2008 135i with 45k miles, bone stock), and noticed if I go WOT for any longer than a few seconds, the car kicks into limp mode, the CEL comes on, and I get misfire codes.

So I bought the log cable and did a 3rd gear WOT run. I only got up to about 3500 RPM before limp mode kicked in. I attach the log.

I've reviewed other people's logs and I cannot immediately see why this is happening on my car.

Can someone review these logs and let me know?

Thanks,
Mike
I can see where it goes into limp mode...

How old are your o2s? Any other codes?

Also- what fuel? May be worth updating your firmware / bef too.



http://www.fuel-it.biz/

e92 AT 335xi 2.0
Doc Race Kit 6062
Fuel-It!Platinum DIY PI Kit + Stage 2BL
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mikstew mikstew is offline
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Default 08-04-2019, 08:43 PM

Quote:
Originally Posted by Dave @ BMS/Fuel-It!
I can see where it goes into limp mode...

How old are your o2s? Any other codes?

Also- what fuel? May be worth updating your firmware / bef too.
Thanks for the reply, Dave.

O2's are probably original, 45k miles.

Fuel is 93 octane pump gas.

There are no other codes. The car works very well when it is on Map 0, and has never thrown a code until I installed Jb4 and ran map 1.

Mike
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Default 08-04-2019, 09:43 PM

Quote:
Originally Posted by mikstew
Thanks for the reply, Dave.

O2's are probably original, 45k miles.

Fuel is 93 octane pump gas.

There are no other codes. The car works very well when it is on Map 0, and has never thrown a code until I installed Jb4 and ran map 1.

Mike
Have u loaded our pump BEF?

Also looks like your running an older firmware too



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mikstew mikstew is offline
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Default 08-09-2019, 07:56 AM

I did some map 4 pulls and attach the logs. Looks like everything is normal.

I am a little hesitant to add yet another modification (Back End Flash) when the only thing that causes the car to not work is the only modification (JB4).

When I bought the JB4, I bought it on the understanding that it would work as a standalone without flashing the car. That was why I bought it because I did not want to flash the car.

Is there any other advice you can offer to help get the JB4 working without flashing?
Attached Files
File Type: csv map 4 pulls.csv (39.6 KB, 16 views)
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Default 08-09-2019, 09:41 AM

Map 4 is basically stock - it’s hard to diagnose off stock values, and can be tough to replicate issues.

It isn’t uncommon for cars to have small issues when a tune is loaded- flash or JB4- tunes in general put a bit more stress on components

Go to map 1 again & log again / read the Misfire codes first



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mikstew mikstew is offline
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Default 08-31-2019, 02:21 PM

Okay I did as instructed.

I did another Map 1 run, read the codes. See the 1400 map attached. Same results. Misfires then limp mode.

Codes were misfire cyl 3 and cyl4 and the multiple cyl misfire code.

Did another map 1 run, read the codes. See the 1414 map attached. Note that the first attempt, I got off the gas. It did not go to limp mode. The second and last pull in map 1414 is the one to look at. Same results: Misfires then limp mode. Afr2 reads 19 at the time of misfires. Codes are misfire cyl 3and cyl4

Let me know what to do next.

Again, these codes cannot be produced if on map4.
Attached Files
File Type: csv 190831_1400.csv (17.9 KB, 13 views)
File Type: csv 190831_1414.csv (12.7 KB, 9 views)
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Default 09-01-2019, 06:49 AM

How old are your plugs & coils?

Seems like your missing on 3/4 consistently- you can replace those coil packs to start, or swap those coils to different cylinders & see if the misfire follows



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mikstew mikstew is offline
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Default 09-07-2019, 02:24 PM

I replaced my plugs, and the two coils on cyl 3/4.

No more misfires and codes.

Thank you, Dave, for helping me through this step by step. I appreciate it!
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Default 09-08-2019, 10:31 AM

Quote:
Originally Posted by mikstew
I replaced my plugs, and the two coils on cyl 3/4.

No more misfires and codes.

Thank you, Dave, for helping me through this step by step. I appreciate it!


Enjoy your Sunday



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