[tylers1027]

Hi all - I posted my question in the B46 forum but was hoping someone in here may have had a similar issue and could provide any insight.

My car is a 2022 330I with AA downpipe, M performance catback and armaspeed intake. After 2 years running JB+ (+3psi) I finally pulled the trigger on a brand new JB4. I installed last weekend and set it to map 1 (+3psi, same I've ran the JB+). I noticed on the highway in high gears when I give it some gas; after a couple seconds it starts to have a jerking/sputtering feeling. I'd never had this with the JB+ and changed my plugs 2K miles ago.

I asked in the JB4 forum and the log they said looked like low octane based on the timing. I'm running 93octane from Shell. I tried removing the JB4 today and put the JB+ back on. Immediately after doing so the jerking/sputtering is gone.

So I guess my question is; if it is poor octane is there a reason why the JB4 would run poorly and not the JB+? And also if this has happened to anyone else?

[mike@x-ph.com]

The results should be identical if you use the same additive +3 PSI on both.

I recommend you reach out to BMS directly

[tylers1027]

Originally Posted by mike@x-ph.com

The results should be identical if you use the same additive +3 PSI on both.

I recommend you reach out to BMS directly

I sent them a question; waiting to hear back. With the JB4 also getting a code about "102A22 MAF, air mass too high". It sounds like online other people have had the same stuttering with JB4 and unplugging the MAF sensor fixes the issue (mostly when have an aftermarket intake). I'll see what BMS says.

[Akaneedles]

Have you updated to the most up to date firmware for the JB4?

[tylers1027]

Originally Posted by Akaneedles

Have you updated to the most up to date firmware for the JB4?

I didn't think I needed to? When I clicked firmware all I saw was the one I already had and then the beta. How do I know if need to update?

[Akaneedles]

Originally Posted by tylers1027

I didn't think I needed to? When I clicked firmware all I saw was the one I already had and then the beta. How do I know if need to update?

I don't think that would be the issue. But I'm sure Burger will ask if your firmware is up to date.

[mike@x-ph.com]

Originally Posted by tylers1027

I sent them a question; waiting to hear back. With the JB4 also getting a code about "102A22 MAF, air mass too high". It sounds like online other people have had the same stuttering with JB4 and unplugging the MAF sensor fixes the issue (mostly when have an aftermarket intake). I'll see what BMS says.

Let us know what they say

[tylers1027]

Originally Posted by mike@x-ph.com

Let us know what they say

Here's the response I got from BMS; not super helpful unfortunately. I'll try to run some better gas and see if the car runs better with the JB4. If not; I'll just stick with the JB+ as never had any problems with the car running poorly with it installed.

"But for that error, it's tuning related and can generally be ignored.

As for lugging your engine...most people don't get on it at 1300 rpms in 6th gear without downshifting and run 20 #'s of boost unless they are a diesel. If you want to get the performance out of your car, you need to be in the proper RPM range as doing that, the car immediately pulls all timing...it's not a good idea."

[Zengineer]

I had sputtering and hesitation under acceleration and was convinced it was bad gas. Threw a CEL; dealer replaced fuel pressure sensor which is apparently a known issue (?) and it’s been better since. I am totally stock and mostly ignorant though, just brainstorming. Good luck!

[tylers1027]

Thanks all for the replies. So I put the JB4 back on, filled up with new gas (Sunoco) and changed the firmware from the v23 pre-installed (beta) to the v22 (stable). Not sure if it was the v23 firmware or the new gas but car seems to be running better now. No more stuttering and the highway shift points seem better too. Fingers crossed I'm all good

[WernerM340IX]

Is there a difference in the feeling of power delivery between the JB+ and JB4?

JB+ goes up to MAX 4 PSI?

Does that correspond to map2 of the JB4?

[tylers1027]

Originally Posted by WernerM340IX

Is there a difference in the feeling of power delivery between the JB+ and JB4?

JB+ goes up to MAX 4 PSI?

Does that correspond to map2 of the JB4?

That's correct; JB+ is +4psi max and map 2 of the JB4 is +4psi. I think the JB+ has more power on the bottom end (since it's just strictly adding +3psi or +4psi no matter what); whereas the JB4 pulls stronger on the topend. I don't know the exact reasoning but I think it's because the JB4 has 4 separate connections (whereas JB+ has only 1) the JB4 is able to read more data and adjust the boost/other parameters accordingly.

[mike@x-ph.com]

Originally Posted by WernerM340IX

Is there a difference in the feeling of power delivery between the JB+ and JB4?

JB+ goes up to MAX 4 PSI?

Does that correspond to map2 of the JB4?

if both tuners are adding the same PSI, the power output should be identical unless something else is going on