[Dfw757]

I bought an N55 F30 this year and installed a JB4 a buddy gave me. I have always have issues when doing a hard pull where the car will hard jerk at the top end of a gear, little puff of smoke and sounds like marbles coming out the exhaust. Drivetrain error pops up sometimes. This happens in map2 and map 5, have not tried the other maps.

I bought a Bluetooth adapter a couple months ago to try and figure out the issue, I tried taking some logs and every time I do a hard pull all the gauges on the JB4 app freeze until I stop logging.

About a week after having the Bluetooth adapter on and trying to do logging my jb4 main board blew with one of the capacitors fried. I figured since that happened maybe the old jb4 was causing issues. But after buying a new board it’s giving the same issues. The wiring harness still looks good I went through and checked all the wiring while it was off the car this week.

I think this also happens when I have no map on but still have the JB4 connected but have not tried this since getting the new main board installed.

I have installed charge pipe, ******* ********, cold air intake and one step colder plugs and new coils since purchasing.

Logs attached

[Steve @ BMS/Fuel-It!]

You'll need to return all your user adjustment settings back to the default settings and then upload a proper log for review.

To properly evaluate the tuning, we'll need a full throttle JB4 log from 40-90mph on a safe private track.

[Dfw757]

Originally Posted by Steve @ BMS/Fuel-It!

You'll need to return all your user adjustment settings back to the default settings and then upload a proper log for review.

To properly evaluate the tuning, we'll need a full throttle JB4 log from 40-90mph on a safe private track.

Steve, my JB4 is new from BMS, I believe it’s at default but could you please provide the correct default settings for me to double check?

[Dfw757]

Originally Posted by Steve @ BMS/Fuel-It!

You'll need to return all your user adjustment settings back to the default settings and then upload a proper log for review.

To properly evaluate the tuning, we'll need a full throttle JB4 log from 40-90mph on a safe private track.

Log with map 2 and I think I also logged map 0, both with sport+ both gave me sudden loss of power when full throttle. It does not do this with the JB4 out of the car. Could it be a bad harness?

[Cannon @ BMS]

Check and properly make sure that all connections and pins are exactly where they should be. Make sure as well that no cables were installed upside down or sideways.

[Steve @ BMS/Fuel-It!]

Per your initial post you got the Jb4 from a buddy and the user adjustment settings are NOT set to the default settings. You'll need to return them to the default settings that can be found here.

F Chassis N55 JB4 - N54Tech.com - International Turbo Racing Discussion

As stated above, I would also recommend going over your install and posting pics for additional assistance.