N54 Jb4 Issue - Pulsating/Uneven Boost

[eazyefromli]

Hey guys, I've done a bunch of searching on the forums and on google and can't seem to find an answer. Sorry if this is something that's been answered, if so, please link to the info!

Anyways, I have a 2010 135i. I purchased a JB4 PnP back in december or january, I can't remember exactly when, but I didn't have a chance to install it until a couple weeks ago (waiting for services, moving across the country, a bunch of stuff came up). I installed it last friday after having my 30k mile service from BMW and have had one major issue.

I noticed that under heavy acceleration (but not full throttle, maybe 3/4 throttle) that my car is not boosting evenly. In any map that I've tried (1, 2, and 5) I'm having issues with the boost 'pulsating'. According to the hijacked boost gauge I am peaking at around 14psi average, but intermittently pulsating between 14psi and around 8psi. Under full throttle I don't really notice any issues.

I was wondering if anyone had any similar problems, and if so, what their solution was.

The only other mod I'm running is a BMS DCI, and I'm running 91 octane at around 3-5k ft altitude.

Thanks.

[Elsabor67]

Check what firmware you have and shoot a log to Terry. If it's what I think it is, it has already been fixed on the firmware because I had a slight pulsating issue before and with the logs that I and others had sent it was fixed.

Also, go here: http://www.n54tech.com/forums/showthread.php?t=10605

There is alot of information adn should be able to find other information too.

Good luck.

[eazyefromli]

Thanks for the response/link. I shot an email over to Terry and I will try updating the firmware. I'm sure this information is available somewhere, but does anyone know the software/hardware requirements for doing the firmware update?

Edit: I'm sorry for asking dumb questions: but is a PC required to create a log from the JB4? I have a mac laptop, but can probably install software to run a PC program if it's necessary.

[mcmn]

a pc is required to log on a mac, you can run vmware or something similar to achieve this


Are you getting a check engine light at all coming on?

It might actually not be the tune, but represent an issue with either your Fuel Pump/Injectors or Ignition Coils/spark plugs.

[Tech112]

I have had a similar problem but at about 20% throttle around 100-130 km/h on all maps except 0. I've tried every firmware for the last year all do the same. I have an N55 though. This pulsing isn't very annoying so I haven't complained yet.

[IZAGLO]

My experience with the JB4 was that it either likes to be driven hard most of the time or mild and the car would run smooth....Unlike the stock tune that is smooth no matter what the JB4 in my experience would also run like crap till the car adapts to either style till a few hard pulls are done, if you want to go fast it would take a few hard pulls to consistanly run smooth. My car would run silky smooth alway's at mild rpms till i wanted to go WOT or three quarater throttle then it would be rough till i did a few hard runs then smooth out...This is the reason i am stock now and will get another tune to try later...I had an issue with the JB4's in-consistancy or rather my inconsistant driving habits...I do like to drive slow at times as our local speed limits on my backroads are 30-50...so......i am not looking for tickets. But i do get some nice pulls in and some aggressive drives on some of the twisties. Right now i am appreciating the stock tune...i love the smoothness!

[foghat]

might want to changes plugs. I had a bit of a hesitation or hiccup when going part throttle in 2nd gear. Changed the plugs and hesitation gone.

[revo 3vom]

I was noticing these same symptoms when i first put the jb4 in... i upgraded my charge pipe and dv's problem seemed to be at bay... on occasion it will hiccup. Most likely a tune issue that will be addressed.

[eazyefromli]

Quick update:

I finally installed the USB cable to the JB4, but I haven't been able to get any logs yet, I still need to find someone with a PC who is willing to come on a high speed mountain drive with me.

However, the problem has gotten worse, to the point that I just keep it on stock mode 95% of the time now; basically any time I'm not doing full throttle pulls.

revo 3vom: I've been considering upgrading my DV's. I had an issue a long time ago with my 95 Audi S6 that was somewhat similar to this problem, and it turned out to be a bad diverter valve. The main difference being that that was a 10+ year old car with 100k+ miles on it, and I was running approximately 100% higher than the stock horsepower. This is a 2 year old car running around a 30% increase from stock horsepower so I'd like to think the stock DV's could handle it.

Anyone have experience with aftermarket/performance DV's or BOV's?

As far as changing plugs goes: I really doubt that's the problem. I have absolutely zero problems in stock mode, no matter how hard I get on it, but in ANY map I have problems, even when I'm not going very hard (although it's much worse when I do go hard on it).

I really appreciate everyones help. I'm going to try to get some logs this week. On a side note: I hit a fucking deer the other day, super excited about that repair bill.

[foghat]

I agree plugs are likely not the issue if your problem is so severe. But Just because you don't have any issues when stock does not mean plugs may not be at least part of the problem. I believe terry recommends doing the plugs about every 24,000 miles when running jb4.

I had about 23,000 miles on mine when I was getting hesitation at part throttle. No hesitation at all when I was stock. New plugs, hesitation gone when using jb4.

[SteveAZ]

I recently did a JB4 install as well and saw similar characteristics. It wouldn't do it all the time, but in the beginning it did it about 50% of the time. I did a couple things at once and it has greatly improved. Not sure if it's the car getting used to the tune, the fact that I changed gas stations (only use Shell or Chevron now, I was using Costco), or the fact that I put an intercooler on. Given I live in Phoenix it's pretty warm here so I've been waiting until the weather cools to really test it and see if I have an issue or not. I can say I noticed an immediate difference with the IC but I was very meticulas about the hoses sealing. Plus I've only had the car for about 1500 miles (it has 26K) with a small fraction of that being run with JB4 so I'm still getting used to it all. It does seem to have improved a lot, however I've only run on map 1 and don't change my settings. Waiting to do a couple more upgrades before I use map 2.

I too need to take logs but when I installed the software it keeps telling me I have a previous version and fails install, haven't gotten serious enough about it yet to really delve in to it but it's coming.

Short term I'm planning on...
new spark plugs
DCI
OCC
DPs (after the first of the year and emissions are done)
Vent gauge (to make it easier to monitor things)
...and will go from there. If all is good and as I gain confidence with the car, I'll go to map 2.

If I'm not happy with it I'll probably go to the COBB, I like the flexability of the JB4 tune, but I don't like all the additional connections and additional processors. Flashing seems like a better way to go and since my car is out of warranty...no worries anyways.

[b1aze]

I have noticed that my hijacked boost gauge will read between 14.5ish to 12 and waver between them in a pull. This could be a few things and it may not actually be varying that much. It could easily be gauge inaccuracy. My IAT hijacked gauge will bounce between a few readings just cruising at 75 on a cool day. I'm talking 10+ degree jumps and I can't imagine it's actually increasing and decreasing that quickly. Until I pull some logs showing boost pressure is varying, I'll chalk it up to gauge variability.

[C4747Z]

Did you ever fix the problem? I was having the same issue with my 1m. It only happened at 70 percent throttle.

[alibaba222]

Did anyone ever figure out the problem?
I'm having the exact dame issue, I haven't done any logs yet but I'm going to, I did s fee things st the same time
Jb4
Charge pipe with tail Bob
And afe intake
Please let me know

[Laboomba2010]

Same issue here. Pulsing power at 50-75 throttle. My car has 73k , I got it at about 50k... the jb4 has only been on for maybe 75-100 miles.

A few days ago I realized I had a totally bizarre part, evidently on this 2010 model there is some sort of sound generator coming off of the charge pipe which I think is absolutely silly (This sound generator thing popped off the charge pipe and I had to clamp it down as firmly as I could with the existing hose clamp) !! Obviously this potentially can cause strange turbulence .

My plans for making the car happy and subsequently making myself happy are, not necessarily in this order: new plugs, probably coil packs (I got some sort of message from BMW about the electronic ignition being a service bulletin), definitely a charge pipe may be next and probably the forge diverter valves. For retaining a somewhat stock but more durable set up, it seems that people like the forge diverter valves. After that I think I have to consider a downpipe but please give me suggestions for the best downpipe I can get while still having catalytic converter's! Also any suggestions on the best spark plugs would be great! Also the best charge pipe for the most reasonable amount of money, this seems like a pretty simple part .

Please please chime in with any knowledge and help you can give me as I am brand new to this tuning thing. I really really love the car and I really really love the potential that the JB4 seems like it can offer the car! Thanks in advance everybody

Barrett