No boost after JB4 install

StuOne19 · 12-18-2021, 12:33 PM

Hello, recently installed a JB4 on my N54 E90 335i xDrive. Did a WOT pull shortly after installing and got a CEL... no big deal, the ECU needs time to adjust, right? I drove ~25 miles and have had the same issue anytime I go WOT. Even under partial throttle, there doesn't seem to be any boost building. I had no issues prior to the JB4 install. I upgraded to the latest firmware and logged 2 runs -- CSV files are attached in the .zip. The first was map0 for a baseline, seems like no boost at all, second was map1 - no boost either. is it possible I disconnected something during install? I do not have the cowl reattached yet.

StuOne19 · 12-18-2021, 12:41 PM

I realized that the pull on map0 didn't seem to fully log, but the data for the pull on map1 is there. what I find the strangest is that boost sits at 0 until a spike when I let off to shift (pedal is 0 and boost is 2.4)

Dave92N54 · 12-18-2021, 07:59 PM

You'll be better off posting this on N54 T3CH as that is run by BMS and they offer extensive JB4 support. Most of us here do not run nor like the JB4.

StuOne19 · 12-19-2021, 04:13 PM

Quote:

Originally Posted by Dave92N54

You'll be better off posting this on N54 T3CH as that is run by BMS and they offer extensive JB4 support. Most of us here do not run nor like the JB4.

thank you! I was about to post over there actually

Navykiller · 12-27-2021, 02:08 PM

Quote:

Originally Posted by StuOne19

thank you! I was about to post over there actually

Sounds like something isnt plugged in correctly. The other place will help further, take some pictures of the install to save yourself some time.

12-18-2021, 12:41 PM	#2
StuOne19 Private First Class 12 Rep 140 Posts Drives: E90 335i xD 6mt, F15 X5 xD35i Join Date: Aug 2015 Location: Chicago iTrader: (1)	I realized that the pull on map0 didn't seem to fully log, but the data for the pull on map1 is there. what I find the strangest is that boost sits at 0 until a spike when I let off to shift (pedal is 0 and boost is 2.4)
	Appreciate 0 Quote

12-18-2021, 07:59 PM	#3
Dave92N54 Major 534 Rep 1,173 Posts Drives: 09 E92 335i 6MT Join Date: Nov 2020 Location: Westminster, Maryland iTrader: (0) Garage List 2009 BMW 335i [10.00]	You'll be better off posting this on N54 T3CH as that is run by BMS and they offer extensive JB4 support. Most of us here do not run nor like the JB4. __________________ 09 E92 335i 6MT / Alpine White / Coral Red / VRSF 7.5" / VRSF DCI / VRSF Catless Downpipes / VTT Charge Pipe / Turbosmart RacePort Gen V / RB OEM Billet Turbos / CD919 Custom Tune / Bilstein PSS9s
	Appreciate 0 Quote