Bank 1 shutdowns, tried everything :(

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
So I've been struggling with this issue for a while now. Bank 1 just shuts down and trims flatline. No codes are thrown. After, I've seen super knock shadow codes for cyls 1-3. It seems to happen more at higher boost / rpm, but no issues triggering it even at just 20psi. Sometimes it will even recover mid-pull.

I've replaced injectors (high and low pressure), hpfp, o2 sensors (bosch adv), 2 step colder plugs, swapped injectors, plugs, and coils between banks, and a handful of other attempts to get to the bottom of this. Nothing works and I'm at my wits end. It always just kills bank 1.

Mods are in sig..

Here's an example where trims flatline and it kills bank 1:

And another where it does it and recovers mid pull:
 
Last edited:
Solution
This turned out to be knock related. Super knock was triggering the open loop. I added some nylon washers and it fixed the issue until I turned it up until about 30psi, then moved to bank 2. I have a set of knock sensors on the way that I'm going to add some pots inline to so I can fine tune.

carabuser

Lieutenant
Oct 2, 2019
550
1
410
0
UK
Ride
Z4 35i & 335i
JB4 logs never make sense to me.

If you can use MHD to log then it would be useful to see the "fuel mode" parameter.
I have looked into a few different fuel issues where injection shuts down and can also provide additional logging parameters in MHD to help find a cause.
 

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
JB4 logs never make sense to me.

If you can use MHD to log then it would be useful to see the "fuel mode" parameter.
I have looked into a few different fuel issues where injection shuts down and can also provide additional logging parameters in MHD to help find a cause.

Unfortunately, not an option. The JB4 is running my port injection, and I don't have enough fueling otherwise to run enough boost to trigger the issue.
 
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doublespaces

Administrator
Oct 18, 2016
9,264
4,271
0
AZ
Ride
2009 E93 335i
Datazap does an extra rotten job plotting those charts on mobile and doesn't include the values from the top of the log like the data graphs here.

Hopefully you find some answers. I've had some lingering fueling issues myself, I think I'm going to install a reflex primarily for the higher resolution logging capabilities.
 

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
Datazap does an extra rotten job plotting those charts on mobile and doesn't include the values from the top of the log like the data graphs here.

Hopefully you find some answers. I've had some lingering fueling issues myself, I think I'm going to install a reflex primarily for the higher resolution logging capabilities.

I don't think it's JB4 or fueling related. My AFRs are generally well controlled and fuel pressure is consistent. The setup worked just fine before I put in built engine/trans and single turbo. The lack of detail as to why it shuts the bank down is super frustrating.
 

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
Just an idea as i don't know what injectors your using. Is it possible your simply running out of injector?

No, my AFRs are solid even up to 36psi of boost. Running 950cc secondaries which flow about 1400cc/min at my pressure levels.
 
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  • Informative
Reactions: SLOWESTN54

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
Her you can see it go open loop, then recover. No fueling issues visible before or after, only horrendous timing pulls showing up. Even with junk gas, I wouldn't expect that at only 20psi of boost.

Screenshot 2022-05-09 175738.jpg
 

Shitrockn54

Lurker
Apr 17, 2022
23
13
0
Ride
335xi
Her you can see it go open loop, then recover. No fueling issues visible before or after, only horrendous timing pulls showing up. Even with junk gas, I wouldn't expect that at only 20psi of boost.
I dont see it going open loop but iam on my cell and datazap makes jb4 logs hard to read for me.
Was it good at all when you put the single and built motor in, or has it bin an issue since the new mods?
What is fol set to?
I set to 0 and tune scaler in the bef
Do you have single rear 02 set for the right rear 02?
Did you use inpa to reset all fuel adaptations theres a second set mhd doesnt reset.
From what i can see you can put more scaler in and reley less on pi my car seems happiest with trims slightly above 25 with hpf 10.
 

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
I dont see it going open loop but iam on my cell and datazap makes jb4 logs hard to read for me.
Was it good at all when you put the single and built motor in, or has it bin an issue since the new mods?
What is fol set to?
I set to 0 and tune scaler in the bef
Do you have single rear 02 set for the right rear 02?
Did you use inpa to reset all fuel adaptations theres a second set mhd doesnt reset.
From what i can see you can put more scaler in and reley less on pi my car seems happiest with trims slightly above 25 with hpf 10.

It's been an issue since. FOL at 0, I've messed with the scalar from 1.1 down to 0.5 with no changes. Rear o2's are disabled. I've reset adaptations with INPA.
 

nyt

Sergeant
Sep 15, 2019
319
1
278
0
Ride
2010 335xi
This turned out to be knock related. Super knock was triggering the open loop. I added some nylon washers and it fixed the issue until I turned it up until about 30psi, then moved to bank 2. I have a set of knock sensors on the way that I'm going to add some pots inline to so I can fine tune.
 
Solution