[catdad]

Hey guys

long time searcher, first time poster here on e90post. I bought my 08 335i a few months back and like most of you went with a Jb4 for obvious reasons.

Recently the car has been running choppy at idle (no codes, brand new coils and plugs, car currently at 59k miles) but i'm not sure it has anything to do with the funky log parameters I observed. This was a 3rd gear pull from around 2k RPM up to auto shift, other runs I did basically mirrored this graph. Only mods on the car are a DCI, cat back exhaust (no DPs), JB4 G4 board, and alpina transmission flash, I run 91 octane gas (stupid California). I can't for the life of me figure out why the heck the throttle parameter is all over the damn place. Car pulls fairly smoothly, during the few 3rd gear pulls I noticed slight hesitation in power but nothing too crazy. I had traction control half way off (pushed the button once briefly). I'm wondering if any of you more experienced tuners or JB4 users can help me figure out what is going on here. Used JB4 map 1.

appreciate it!

[mike@x-ph.com]

For help you need to post the csv file.
Lots of throttle closure, do you have DSC completely off?

[Mike@N54Tuning.com]

Yes good point, make sure the nannies are off when logging.

Mike

[catdad]

I did another quick run thinking the same thing with the traction control all the way off, and the graph looked almost identical to the one in my original post. I will post the original run .CSV file for you guys.

[catdad]

Originally Posted by Mike@N54Tuning.com

Yes good point, make sure the nannies are off when logging.

Mike

Just for good measure, here is the .csv and graph of the run I did with traction completely disabled. It's shorter than the first due to a stop sign that I didn't want to run....lol.

[mike@x-ph.com]

are you pressing on the traction control button for 5-10 seconds until you see a yellow triangle ?

[brecken]

I don't really know a whole lot so I could be completely wrong but over boost can also cause throttle plate closures and it looks based on the log every time your actual boost gets near or just over the requested boost you the throttle closes

[catdad]

Originally Posted by mike@x-ph.com

are you pressing on the traction control button for 5-10 seconds until you see a yellow triangle ?

Yep, traction was fully disabled, yellow triangle and all.

[mike@x-ph.com]

Originally Posted by pianoman224

Yep, traction was fully disabled, yellow triangle and all.

Originally Posted by brecken

I don't really know a whole lot so I could be completely wrong but over boost can also cause throttle plate closures and it looks based on the log every time your actual boost gets near or just over the requested boost you the throttle closes

You are correct,throttle closure looks to be caused by overboost
thats why i need the excel file to check overboost.

[catdad]

Originally Posted by mike@x-ph.com

You are correct,throttle closure looks to be caused by overboost
thats why i need the excel file to check overboost.

I uploaded both files above in a .txt format since the forum doesn't let us upload .csv, if you download the file and then change the extension back to .csv you will be able to view it in excel or the jb4 interface.

Appreciate all the help and insight Guys!

[Mike@N54Tuning.com]

The log is from an older JB4 G4 system. They were obsoleted in 2012. For what it is its probably fine but I'd suggest upgrading to a JB4 G5 ISO board for $150. It offer much better boost and throttle control.

Mike

[catdad]

Originally Posted by Mike@N54Tuning.com

The log is from an older JB4 G4 system. They were obsoleted in 2012. For what it is its probably fine but I'd suggest upgrading to a JB4 G5 ISO board for $150. It offer much better boost and throttle control.

Mike

I have been thinking about that over the past couple of weeks. Would the G5 board make a big enough difference based on the limited amount of mods that I currently have?

I live in California where BMS will not ship, unfortunately, so I would probably have to get it second hand from someone.

[mike@x-ph.com]

Originally Posted by pianoman224

I uploaded both files above in a .txt format since the forum doesn't let us upload .csv, if you download the file and then change the extension back to .csv you will be able to view it in excel or the jb4 interface.

Appreciate all the help and insight Guys!

Looks like the car is overboosting.
Contact Terry and check if he can adjust that for you.

[Mike@N54Tuning.com]

Originally Posted by pianoman224

I have been thinking about that over the past couple of weeks. Would the G5 board make a big enough difference based on the limited amount of mods that I currently have?

I live in California where BMS will not ship, unfortunately, so I would probably have to get it second hand from someone.

The G5 ISO is a lot better. Peak power will be similar but its much smoother and has a lot more tuning function than the old G4 had.

Mike