JB4tech.com - International Turbo Tuning Discussion
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int_c0m8U$tion int_c0m8U$tion is offline
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Default Boost Spike and Fuel code help - 05-15-2022, 06:50 AM

First issue, I would like to get thoughts on how to fix a boost spike that occurs every time I release throttle to shift or just quickly release throttle. What appears to be happening is boost is dumped closing the TB causing a spike before boost is dumped through BOV.

I have tried three different TialQ springs to fix the issue. Black for 6psi (fully open valve at idle), white 8psi (valve is about 80% open) and natural 10 psi (valve is closed to slightly open at idle. Still got the spike but it wasnít as severe with the black spring.

Are there settings in the JB4 that can fix this through the tune? Or maybe this is just normal. Iíve see other logs with the spike but not as seemingly severe.

Mods
Running map 1 jb4
Dci
Charge pipe with BOV - 1/4 line connected to BMS vacuum adapter
7.5 intercooler
BMS external pcv dual catch can

2nd help item. I gave two recurring codes that I can clear and will not return until the car is shut off and started again. The codes are (2022-05-12 07_03_08: 2AAF Fuel pump, plausibility 2D2E Angle of throttle valve - intake pipe underpressure, correlation).

Iíd be great full have someone look at my logs to see if they could identify anything wrong. Looks like my lpfp readings are healthy. No idea on the throttle valve issue.

Much appreciated!!
Attached Files
File Type: csv P32_M1_R3_220514_1746.csv (40.0 KB, 20 views)
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int_c0m8U$tion int_c0m8U$tion is offline
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Default 05-16-2022, 09:44 AM

Iím new to posting for support. Iím grateful to this community as it has been my go to source for research, learning, and DIY. I hope to contribute so that I can pay it forward.

If Iíve posted this in the wrong area, would someone be kind enough to point me in the right direction.

Any help would be greatly appreciated. Thank you!
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Cannon @ BMS Cannon @ BMS is offline
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Default 05-18-2022, 12:56 PM

The boost spike when you let off is totally normal, nothing to worry about. When the throttle body closes, the air that is now blocked off has no where to go. Therefore pressure within the charge pipe increases until it can be vented. That's the spike you are seeing.
A couple questions..
What BEF are you on?
What fuel are you running?
When was the last time the O2's were changed?


Burger Motorsports
Home of the JB4 the worlds most popular turbocharged tuning system!

It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please click here for more information on legal requirements related to use of BMS parts.
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Cannon @ BMS Cannon @ BMS is offline
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Default 05-18-2022, 12:57 PM

The boost spike when you let off is totally normal, nothing to worry about. When the throttle body closes, the air that is now blocked off has no where to go. Therefore pressure within the charge pipe increases until it can be vented. That's the spike you are seeing.
A couple questions..
What BEF are you on?
What fuel are you running?
When was the last time the O2's were changed?


Burger Motorsports
Home of the JB4 the worlds most popular turbocharged tuning system!

It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please click here for more information on legal requirements related to use of BMS parts.
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int_c0m8U$tion int_c0m8U$tion is offline
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Default 05-18-2022, 03:19 PM

Hi Cannon. I really appreciate the feedback. It’s Reassuring to have you look into my logs and questions.

No back end flash. Just JB4 map 1. I’ve got a couple more mods planned before I move to map 5 and look into a BEF.

2012 bmw 335is with 105k miles on original o2 sensors. Running pump fuel 93 octane.
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Cannon @ BMS Cannon @ BMS is offline
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Default 05-23-2022, 04:51 PM

We highly recommend getting a BMS BEF. They are free to use, just need the MHD BEF JB4 Flasher.


Burger Motorsports
Home of the JB4 the worlds most popular turbocharged tuning system!

It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please click here for more information on legal requirements related to use of BMS parts.
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int_c0m8U$tion int_c0m8U$tion is offline
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Default 05-23-2022, 06:28 PM

I can pick one up. Can you elaborate a bit on how itll address my particular situation with the codes. Also is there something specific that you are thinking of that will benefit me in particular. Thanks again. I’ll try to get one and have it hooked up. In a couple weeks I should have time to install catted dp’s and inlets.
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Default 05-28-2022, 05:54 AM

Hello! I got the MHD flasher and flashed the ecu to BEF JB4_MHD_INA0S_PUMP_2. Running post flash JB4 Map 1 with the menu four setting changed to 2. I was confused about the _2 at the end of the flash name assuming their would be a _1 but there was not so please let me know if I should be using a different flash. Iím on pump gas and factory turbos.

Would you consider taking another look at my logs. It appears everything is within acceptable ranges.

One thing I noticed is that my low pressure fuel pump readings are more sporadic. Iím assuming this is normal and what was being logged in the initial pre flash log attached was likely off or fixed by the BEF. currently they appear to be steady at 60-70. Is this a healthy pump or would you consider changing it? Eventually I was planning to upgrade it but it was not a priority just yet. Current pump is oem original to the car and has 105k miles on it. Idle or coast readings are 65 but jump randomly to 71//72. Before the flash, it was typically pegged at 75/76. Hpfp readings look healthy to me but Iím no expert, thoughts on this (does everything look ok)?

Also noticed a timing correction that is showing up on each pull on cylinder 2. Got the nexsys b58 upgrade system on the way so hopefully that will fix the timing a bit. Any suggestions on if the timing correction is a concern? Currently running elder coils and stock Bosch plugs that are less than 10k miles. Oh and before the flash i couldnít get timing readings on all 6 cylinders. Only cylinder 1. I think itís a setting issue or capability issue with the jb4 running on a 335is.

Lastly, AFR seems about right. Would you take a peek and confirm.

I appreciate any advice or guidance you or any other members in the community can provide!
Attached Files
File Type: csv P32_M1_R12_220527_1636.csv (186.5 KB, 18 views)
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Default 06-07-2022, 05:57 PM

Log doesn't look too bad, when was the last time the O2's were changed?


Burger Motorsports
Home of the JB4 the worlds most popular turbocharged tuning system!

It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please click here for more information on legal requirements related to use of BMS parts.
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