[gnutzie]

Hi,

I'm experiencing an issue with overboost / boost creep that I can't figure out.
The boost is always waaay over target regardless of Map. If I go more than 40-50% throttle it will boost beyond 20psi and protection mechanisms starts kicking in.

In other words - it seems like the PWM signal to the wastegate is always 100%

Long story short - I think I've pinned it down to an issue with the JB4 unit.
This is because if I put menu 4 into stock map (bypass mode) and also plug the wastegate actuator wiring back to the stock harness, everything works fine.

I've gone back to what I believe is stock settings throughout the system. I've attached an example of a configuration that I have tried.

The system was working fine for a long time until it started acting up.
I would love some pointers, either to help me find the problem or to diagnose if the unit is faulty.

Car:
2011 BMW 135i (Australia) N55, vacuum controlled wastegate
Mods: BMS IC, VSRF ******* down pipe, BMS intake, BMS charge pipe
98 octane fuel.

[Cannon @ BMS]

Please upload CSV log files. Thanks!

[gnutzie]

I have attached a log file from the archive that I think shows the problem

[Steve @ BMS/Fuel-It!]

Looks like the wastegate is stuck closed.

Can I see a log on map 4 with the JB4 connected to the boost solenoid and one without it connected?

[gnutzie]

I will get some logs today.
Which setting do you want Menu 4?

[gnutzie]

I kept menu 4 at 4 for now.
The attached logs should show 4 pulls at about 50-60% pedal.

The first two are with wastegate actuator straight to stock harness
The second two are with actuator connected through JB4

The logs should show the boost creeping up towards 20 psi on the last pull

[Steve @ BMS/Fuel-It!]

Why would you run menu 4 option 4 with the wastegate connector installed? Are you trying to control boost with the JB4 or just run it for the gauges?

[gnutzie]

I have been running menu 4 at 4 with the wastegate actuator connected to the stock harness, because this is the only way I can avoid the boost creep. I want to go back to being fully enabled to control boost but it’s not drivable like that currently

I reconnected it to the JB4 because you asked me for a log with it connected.

If you want me to log with menu 4 in a different setting then let me know.

[Cannon @ BMS]

Try going back to default settings and see if that eliminates the boost creep.

[Steve @ BMS/Fuel-It!]

Originally Posted by gnutzie

I have been running menu 4 at 4 with the wastegate actuator connected to the stock harness, because this is the only way I can avoid the boost creep. I want to go back to being fully enabled to control boost but it’s not drivable like that currently

I reconnected it to the JB4 because you asked me for a log with it connected.

If you want me to log with menu 4 in a different setting then let me know.

Yes...I wanted to see the difference. If running menu 4 set to option 4, JB4 has no boost control and you can see that there is no WGDC coming from the JB4.

Do you have a flash loaded? If so, set menu 4 to option 2 and lets see a log on map 4 with the boost solenoid wires connected. If not, set menu 4 to option 3 and do the same.

[gnutzie]

Thanks for clarifying.
I am currently away but will collect the logs next week and post them here

[gnutzie]

Did a log run today, menu 4 set to 3 and Map 4
First pull is wastegate actuator connected to stock harness
Second pull is connected to JB4

The logs show the problem clearly

[Cannon @ BMS]

Please upload a log at 100% pedal input

[gnutzie]

I tried but the car ****s itself when the JB4 is connected. I guess some safety mechanisms kick in.

See attached log. This time JB4 connected comes first.

[Cannon @ BMS]

Please record a log on map 0.

[Terry @ BMS]

Attach a photo of the JB4 control board inside the enclosure also please.

[gnutzie]

Thanks again for the support so far.
I'm away again so will provide what you have asked when I'm back in two weeks.

Just as a remark my previous tests show similar behavior in all maps (ie 0,1,2,4,5). I understand you might be looking for some specifics in the logs but I just thought I'd mention it.

Since you are asking for a picture of the circuit board I guess you are suspecting a faulty board at this point?

[Terry @ BMS]

Diode not clipped.

Just leave it on map0 until I see the photo.

[gnutzie]

See attached

[gnutzie]

Had a closer look and I can see one of the 4 diodes has been cut or broken
Is that correct for my board? I had the impression that I have a later revision board that shouldn’t need any cutting

[Steve @ BMS/Fuel-It!]

This could be a sticking wastegate.

How old is the JB4?

Have you installed a down pipe recently?

[gnutzie]

If the waste-gate was sticking wouldn't the problem be present also when bypassing the JB4?

I purchased the JB4 September 2019, so it is about 2 years old.

VRSF 3.5" de-*** down pipe was installed at the same time.

[Steve @ BMS/Fuel-It!]

It was...that's why I had you run map 4.

[gnutzie]

I'm not sure what you mean.

The car runs fine in map 4 as well - as long as I connect the wastegate actuator to the stock harness.

As soon as I connect the JB4, the wastegate goes straight to fully closed, even when the car is in idle. I can see it visually by looking at the wastegate linkage and connecting/disconnecting the JB4.

[gnutzie]

It’s also worth mentioning that while troubleshooting i also connected a PWM to the wastegate actuator to test how responsive it was. The wastegate was opening/closing instantly and could be set to any range without sticking