[mattgc13]

I have been dealing with this issue for awhile, and have tried a bunch of JB4 settings. Any suggestions are welcome I have run out of ideas. As you can see on these logs (it combined two logs taken within 10 minutes), my boost spikes very high during the beginning of a WOT pull. It feels like it is bucking when it cuts my boost off, usually it kicks me down to map 4, a few times it has even thrown me into limp mode. In between these runs I cleared my codes, which also are a mystery to me. Today I unplugged all connections on my JB4, except fuel rail because it's a pain in the ass, and cleaned them all to ensure that wasn't an issue. The airmass too low code can be ignored I believe that was from me starting the car with my intake off earlier today, chasing down a whining noise in that area under the intake, near the fuel pump but it seems like the alternator to me. None of these attached codes have thrown a check engine light, idk if this has to do with the BEF? Previously it was suggested to me to check my wastegate arm to see if it was physically hitting my dp coupling, and I have confirmed that is not the case. The codes coming up are pretty random seeming, and don't really stay consistent, not sure if they are related at all. When driving car normally it is completely fine.

I am running ******* dp, step colder plugs, 91 octane and JB4 + BEF on a 2011 6MT 335i e90. I have messed with ethanol mixes (e54 in arizona ), did not help my situation lol.

[mattgc13]

Originally Posted by mattgc13

I have been dealing with this issue for awhile, and have tried a bunch of JB4 settings. Any suggestions are welcome I have run out of ideas. As you can see on these logs (it combined two logs taken within 10 minutes), my boost spikes very high during the beginning of a WOT pull. It feels like it is bucking when it cuts my boost off, usually it kicks me down to map 4, a few times it has even thrown me into limp mode. In between these runs I cleared my codes, which also are a mystery to me. Today I unplugged all connections on my JB4, except fuel rail because it's a pain in the ass, and cleaned them all to ensure that wasn't an issue. The airmass too low code can be ignored I believe that was from me starting the car with my intake off earlier today, chasing down a whining noise in that area under the intake, near the fuel pump but it seems like the alternator to me. None of these attached codes have thrown a check engine light, idk if this has to do with the BEF? Previously it was suggested to me to check my wastegate arm to see if it was physically hitting my dp coupling, and I have confirmed that is not the case. The codes coming up are pretty random seeming, and don't really stay consistent, not sure if they are related at all. When driving car normally it is completely fine.

I am running ******* dp, step colder plugs, 91 octane and JB4 + BEF on a 2011 6MT 335i e90. I have messed with ethanol mixes (e54 in arizona ), did not help my situation lol.

Also want to include, during my second pull I let off because it was cutting boost so bad it did not feel very healthy. Also scanned codes after run 2 and nothing came up, but it did kick me to map 4 after the second run.

[Terry @ BMS]

A few things going on here.

For starters lets see a photo of the JB4 control board inside its enclosure.

[mattgc13]

Originally Posted by Terry @ BMS

A few things going on here.

For starters lets see a photo of the JB4 control board inside its enclosure.

I bought this used, silly of me to assume the diode was cut but I guess I may have neglected looking into that, do I need to do that? The solder on the outer black one looks not very intact...

[Payam @ BMS]

Diode is supposed to be cut for E series if you have soldered it back together, that might be the issue.

[mattgc13]

Originally Posted by Payam @ BMS

Diode is supposed to be cut for E series if you have soldered it back together, that might be the issue.

I did not mess with anything on the board since I got it. I couldnt really find any examples of the E9x n55 boards with a diode cut, should I cut that far left black diode completely out?

[Terry @ BMS]

Yes, cut the diode, then relog.

[mattgc13]

Originally Posted by Terry @ BMS

Yes, cut the diode, then relog.

Ok I will complete that later today. Just to confirm, this is the correct diode that needs to be cut?

[mattgc13]

Alright, figured it out by looking at the F series n55 boards, literally couldnt find anywhere else with a specified picture of that diode being cut for the e series n55, but I figured it was the same. I cut the diode, and reflashed the iso for good measure. Im not sure if it is placebo effect, but it did seem smoother, however it still bucked a few times and kicked me into map 4 on my final run. Attached are a couple runs that I did the one with the time 20:38:38 was a full pull that kicked me into map 4, and was still severely overboosting.

[mattgc13]

Originally Posted by Terry @ BMS

Yes, cut the diode, then relog.

Any thoughts on the above logs Terry? Thank you

[Terry @ BMS]

Still over boosting, photo of cut diode?

Unplug blue solenoid connection leaving solenoid disconnected and do another map1 log to confirm boost is stuck at 3psi.

[mattgc13]

Originally Posted by Terry @ BMS

Still over boosting, photo of cut diode?

Unplug blue solenoid connection leaving solenoid disconnected and do another map1 log to confirm boost is stuck at 3psi.

This is the cut diode, I will log with boost solenoid unplugged tonight. Thank you so much for your help.

[Steve @ BMS/Fuel-It!]

Next will be inspecting your wastegate operation and make sure it's not stuck or hitting anything.

[mattgc13]

Originally Posted by Steve @ BMS/Fuel-It!

Next will be inspecting your wastegate operation and make sure it's not stuck or hitting anything.

This is what I initially checked, someone suggested this before and it seemed plausible because it began awhile after installing a new ********. I checked the coupling orientation and it seemed to give the wastegate full actuation range. I did not do any further tests to check the wastegate, what other steps could I take to make sure its operating correctly? Could it be my boost solenoid? Maybe a cracked vacuum line? I also want to clarify I am running the pump BEF with ACN 91 currently, not sure if that would make any difference.

[mattgc13]

Originally Posted by Terry @ BMS

Still over boosting, photo of cut diode?

Unplug blue solenoid connection leaving solenoid disconnected and do another map1 log to confirm boost is stuck at 3psi.

This was a log in map 1 with boost solenoid completely disconnected.

[mattgc13]

The car was feeling healthy and I recorded a few pulls on the 24th. It did not overboost and seemed pretty solid. Did one in map 4 and map 1. This has been another problem, usually I can reproduce the issue, but sometimes it seems perfectly fine. My car also has started consuming a lot of oil recently and the exhaust is full of black smoke sometimes...seeming like ill be getting new turbos soon, regardless would like to figure out the culprit of this overboosting issue so I don't damage new turbos/my engine in the future. I have just been using map 4 when driving the car recently to be safe.

[Steve @ BMS/Fuel-It!]

The logs look pretty good BUT, cylinder 4 is seeing a lot of corrections. Have you had a compression test done given you're burning oil like you are and those timing corrections.

[mattgc13]

Originally Posted by Steve @ BMS/Fuel-It!

The logs look pretty good BUT, cylinder 4 is seeing a lot of corrections. Have you had a compression test done given you're burning oil like you are and those timing corrections.

I have not...I will try to do that this weekend. What is the ideal compression for N55?

[Steve @ BMS/Fuel-It!]

Up around 200psi but that can vary based on your equipment. Biggest thing would be seeing if all 6 cylinders are close.

[mattgc13]

Originally Posted by Steve @ BMS/Fuel-It!

Up around 200psi but that can vary based on your equipment. Biggest thing would be seeing if all 6 cylinders are close.

Thanks so much steve, I will see what I can do this weekend and let you know my findings.

[mattgc13]

I did a compression test today, and these were the results
Cylinder 1-165-170
Cylinder 2 - 170-175
Cylinder 3 - 155-160
Cylinder 4 - 145
Cylinder 5 - 170
Cylinder 6 - 170

This doesn't seem very reassuring but I am just about to hit 100k miles, how bad is that given the engine age? I've started noticing an occasional slight stumbling at idle as well. Whole engine is going to **** it seems like! Would this probably indicate bad piston rings or valves? Would it be wise to look into an engine rebuild before getting new turbos? The money pit continues...

Ive also attached some pictures of the sparkplugs that were pulled out, cyl 3 and 4 were pretty oily. Didn't pull out the endoscope this time but from what I could see inside it was pretty drenched in there. I did plugs and coils about 10k-15k ago and they were completely dry, which was immediately after I installed jb4 and it fried a coil pack, replaced all 6 with delphi coils and step colder plugs.

[Steve @ BMS/Fuel-It!]

Given that cylinder 4 has timing corrections, low compression, and oily plugs...no, I would not upgrade the turbo and consult an INDY to see what direction you want to go.