[locolok]

Forgive my ignorance and questions, but I don't quite understand what stft and ltft are and I would like to learn, I know that bank 1 and bank 2 have to be within a percentage of difference, but where are those values taken from? what is the sensor that measures it and where is it? what is bank 1 and bank 2? is the amount of fuel managed by the injection ramp? Could someone explain to me how this works?

[Jnat]

Originally Posted by locolok

Forgive my ignorance and questions, but I don't quite understand what stft and ltft are and I would like to learn, I know that bank 1 and bank 2 have to be within a percentage of difference, but where are those values taken from? what is the sensor that measures it and where is it? what is bank 1 and bank 2? is the amount of fuel managed by the injection ramp? Could someone explain to me how this works?

B58 log review is a thread started by kern417 and it's pretty comprehensive especially for a beginner asking questions.
stft is short term fuel trim - this is the immediate fuel trim rich or lean represented by a positive or neg
ltft is long term fuel trim - this is a learned value over time

bank is normally referred to on four 02 sensor engines like a true twin turbo N54 and each bank would have an upstream (front of converter) and downsstream (behind the converter) sensor... the front sensor is used for fuel/trim and the rear 02 is used to monitor the converter... if they are mirroring each other you either have no cat or not enough cat...

that's enough from me, do some research starting with the log review thread, you'll pick up a lot information...............

[locolok]

Originally Posted by Jnat

B58 log review is a thread started by kern417 and it's pretty comprehensive especially for a beginner asking questions.
stft is short term fuel trim - this is the immediate fuel trim rich or lean represented by a positive or neg
ltft is long term fuel trim - this is a learned value over time

bank is normally referred to on four 02 sensor engines like a true twin turbo N54 and each bank would have an upstream (front of converter) and downsstream (behind the converter) sensor... the front sensor is used for fuel/trim and the rear 02 is used to monitor the converter... if they are mirroring each other you either have no cat or not enough cat...

that's enough from me, do some research starting with the log review thread, you'll pick up a lot information...............

Thank you very much for the reply.

I rely on the Google translator because my English is very bad and it is difficult for me to understand certain things

I understand then, that those values ​​come from the pre-catalyst and post-catalyst lambda probe, but in my case I have a downpipe installed, with a spacer with a mini-catalyst for the post-catalyst probe to eliminate the cel, the signal that the probe picks up post catalyst would not be falsified?

[vcx]

that would be so great to have a thread/post with all the logging parameters explained.. so hard to find informations on some sensors/values

[Jnat]

Originally Posted by locolok

Thank you very much for the reply.

I rely on the Google translator because my English is very bad and it is difficult for me to understand certain things

I understand then, that those values ​​come from the pre-catalyst and post-catalyst lambda probe, but in my case I have a downpipe installed, with a spacer with a mini-catalyst for the post-catalyst probe to eliminate the cel, the signal that the probe picks up post catalyst would not be falsified?

If you are running a spacer, yes it's falsified...

[eluded]

Originally Posted by kern417

thanks for sharing. that's my video.

U have the best vids

[kern417]

Originally Posted by weehe126

A leaking injector can be shown by the afr taking longer to reach max value when you let off the gas. When you let off the gas and are engine braking there should be no gas coming from the injectors, so you have infinite air. If it takes a second or 2 to reach max afr value,you might have a leaking injector. He was just correcting what you said, as you said it backwards. Your comment/question isn't a realistic situation.

another way you can feel it is the car doesn't stop accelerating because of the fuel pumping in the cylinder. it can be an unnerving feeling if it doesn't shut off properly when you lift off the pedal.

[kern417]

Originally Posted by locolok

Thank you very much for the reply.

I rely on the Google translator because my English is very bad and it is difficult for me to understand certain things

I understand then, that those values ​​come from the pre-catalyst and post-catalyst lambda probe, but in my case I have a downpipe installed, with a spacer with a mini-catalyst for the post-catalyst probe to eliminate the cel, the signal that the probe picks up post catalyst would not be falsified?

Just a correction - bank 1 and bank 2 are for cars with 2 separate sets of headers/manifolds. This applies primarily for V8s that have 2 separate headers, or twin turbo cars (N54, S55, etc) that have 2 separate catalytic converters.

sensor 1 and sensor 2 are before and after the cat. only sensor 1 measures afr.

you will not see sensor 2 as a direct reading in logs but some data indicates it has an effect on fuel trims.

sorry if that made it more confusing.

[kern417]

Originally Posted by vcx

that would be so great to have a thread/post with all the logging parameters explained.. so hard to find informations on some sensors/values

Hopefully this can help you in the right direction
https://f30.bimmerpost.com/forums/sh....php?t=1648722

[BMWILUVU]

Originally Posted by kern417

another way you can feel it is the car doesn't stop accelerating because of the fuel pumping in the cylinder. it can be an unnerving feeling if it doesn't shut off properly when you lift off the pedal.

If it got that bad, it wouldn't really do this, it would rather produce more intense pops, burbles, and misfires detected off the crankshaft sensors. At fault injectors and boost usually shutdown shortly as safeties.

[blacksapphire440i]

Originally Posted by BMWILUVU

If it got that bad, it wouldn't really do this, it would rather produce more intense pops, burbles, and misfires detected off the crankshaft sensors. At fault injectors and boost usually shutdown shortly as safeties.

So lets say you're on OEM burbles tuned and on catless downpipes. Sometimes you get some nice loud pops here and there when down shifting but I assume you mean your normal burble settings turn more into like pops and bangs/flames?

[B58]

Originally Posted by blacksapphire440i

So lets say you're on OEM burbles tuned and on catless downpipes. Sometimes you get some nice loud pops here and there when down shifting

I have my burbles turned off and I still get short burbles when down-shifting only in sport mode or even letting off the pedal in sport mode. I have a cat-less dp, AWE mid pipe, and the MPE so I'm assuming its part of the MPE nature with no resonated mid pipe which makes it more audible. If anyone knows a fix to this please chime in lol. I remember back in 2018 I still had minor burbles with just a cat-less dp and the MPE with stock mid-pipe running a JB4 only.

[locolok]

Originally Posted by kern417

Just a correction - bank 1 and bank 2 are for cars with 2 separate sets of headers/manifolds. This applies primarily for V8s that have 2 separate headers, or twin turbo cars (N54, S55, etc) that have 2 separate catalytic converters.

sensor 1 and sensor 2 are before and after the cat. only sensor 1 measures afr.

you will not see sensor 2 as a direct reading in logs but some data indicates it has an effect on fuel trims.

sorry if that made it more confusing.

Thanks again kern, so I should just monitor stft without further ado and watch for +/-10% corrections, right?

[BMWILUVU]

Originally Posted by blacksapphire440i

So lets say you're on OEM burbles tuned and on catless downpipes. Sometimes you get some nice loud pops here and there when down shifting but I assume you mean your normal burble settings turn more into like pops and bangs/flames?

If its a slight leak then you may not notice it as much as its usually one injector but as it get worse where the quantity of fuel leaked gets to the point where you are now not burning gas completely in the piston your burbles and pops in the headers, turbo, and downpipe get pronounced and you may even get loud bangs and that is why boost is usually shutdown by the ecu at a certain point.

[blacksapphire440i]

Originally Posted by BMWILUVU

If its a slight leak then you may not notice it as much as its usually one injector but as it get worse where the quantity of fuel leaked gets to the point where you are now not burning gas completely in the piston your burbles and pops in the headers, turbo, and downpipe get pronounced and you may even get loud bangs and that is why boost is usually shutdown by the ecu at a certain point.

Damn I see how can you tell if you have a slight leak? this is a log that ive recently taken not sure if youre able to figure it out via log or not https://www.bootmod3.net/log?id=6303...0b432dfabc91f2

[BMWILUVU]

Originally Posted by blacksapphire440i

Damn I see how can you tell if you have a slight leak? this is a log that ive recently taken not sure if youre able to figure it out via log or not https://www.bootmod3.net/log?id=6303...0b432dfabc91f2

Your 3rd pull looks fine not sure whats going on on the first 2 pulls and with cylinder 2. I would log more and see if the behavior is repetitive. As far as leaky injectors, as I said, if your injectors are just slightly leaking, its hard to tell. Once it gets more serious and starts to dump gas stuck open then you will definitely know but as I said unless it fails right-away, usually a leaky injector will leak little then more and more over time. You just need to keep an eye on gradually degrading symptoms like sooty exhaust, rich smell at exhaust (tougher to do if you are catless since it always smells rich), declining mpg efficiency, ltft trending negative. Once you have symptoms that elude to something is developing, I'd try to identify by inspecting plugs and cylinder head to see the odd man out. Another symptom is that leaky injector signs are more easily spot when starting up cold and idle rpms. When you shutdown and startup, the leaky injector will continue to drip more than the others and the pool of fuel will often show itself in an unusually larger puff of white smoke on a cold startup. Also, 9 times out of 10 people post about leaking injectors or failure the guy is tuned and I can't even remember the one who wasn't tuned but I just put it out there. I had a conversation about this with a Bosch techrep about this model injector for the B58 some ways back. These Bosch injectors don't just go bad for no good reason. If you are tuned just watch yourself just look at all of the injector posts on the forums these days. Maybe as Kern said they're getting a bit aggressive on the later maps.

[blacksapphire440i]

Originally Posted by BMWILUVU

Your 3rd pull looks fine not sure whats going on on the first 2 pulls and with cylinder 2. I would log more and see if the behavior is repetitive. As far as leaky injectors, as I said, if your injectors are just slightly leaking, its hard to tell. Once it gets more serious and starts to dump gas stuck open then you will definitely know but as I said unless it fails right-away, usually a leaky injector will leak little then more and more over time. You just need to keep an eye on gradually degrading symptoms like sooty exhaust, rich smell at exhaust (tougher to do if you are catless since it always smells rich), declining mpg efficiency, ltft trending negative. Once you have symptoms that elude to something is developing, I'd try to identify by inspecting plugs and cylinder head to see the odd man out. Another symptom is that leaky injector signs are more easily spot when starting up cold and idle rpms. When you shutdown and startup, the leaky injector will continue to drip more than the others and the pool of fuel will often show itself in an unusually larger puff of white smoke on a cold startup. Also, 9 times out of 10 people post about leaking injectors or failure the guy is tuned and I can't even remember the one who wasn't tuned but I just put it out there. I had a conversation about this with a Bosch techrep about this model injector for the B58 some ways back. These Bosch injectors don't just go bad for no good reason. If you are tuned just watch yourself just look at all of the injector posts on the forums these days. Maybe as Kern said they're getting a bit aggressive on the later maps.

This was a 4th gear pull and thanks for the info regarding the injectors. I do not think mine are leaking atm but I will definitely change them. This is another log when the season was spring w/ cooler temps https://www.bootmod3.net/log?id=62c3...0b43047115b91e

[B58]

B58 injectors are fairly cheap. You can always buy 6 of them and have them sitting around or just swap them out for a peace of mind. I rather spend $1,000 on injectors and swap them out at home than have to drop money on a new motor. The B58 is delicate when it comes to leaking injectors. I had 2 scored up cylinder walls. The N54's are notorious for leaking injectors, but they are more forgiving and those injectors now cost $3,000 for a 6 pack so lets hope the B58 doesn't creep up in pricing.

[gantona]

Originally Posted by blacksapphire440i

This was a 4th gear pull and thanks for the info regarding the injectors. I do not think mine are leaking atm but I will definitely change them. This is another log when the season was spring w/ cooler temps https://www.bootmod3.net/log?id=62c3...0b43047115b91e

I looked at your logs, and as far as I know, it looks very solid.
I can't see any evidence of leaking injector (please experts, correct me if I'm wrong).
actual AFT match pretty nicely target AFR.
STFT is from 0.92 to 1.

On the first log, when you lift accel pedal, we can see AFR going up immediately. If one injector was leaking, AFR should take a bit of time to go up

I just noticed some dips in hpfp when shifting, but it may be normal. I don't know


If someone things this logs can show leaking injector, please explain. I really need to understand where.

[BMWILUVU]

Originally Posted by blacksapphire440i

This was a 4th gear pull and thanks for the info regarding the injectors. I do not think mine are leaking atm but I will definitely change them. This is another log when the season was spring w/ cooler temps https://www.bootmod3.net/log?id=62c3...0b43047115b91e

I don't think you need to change any injectors unless you are experiencing specific symptoms. Its unnecessary cost and effort. For example, if you are getting misfires without leaky injector symptoms, do the usual and check plugs and coils first.

[blacksapphire440i]

Originally Posted by BMWILUVU

I don't think you need to change any injectors unless you are experiencing specific symptoms. Its unnecessary cost and effort. For example, if you are getting misfires without leaky injector symptoms, do the usual and check plugs and coils first.

Alright for sure. I've at 47k miles and I got the car at 28k miles so I was just thinking once I up the boost with PI that it would be good preventative maintenance.

[blacksapphire440i]

Originally Posted by gantona

I looked at your logs, and as far as I know, it looks very solid.
I can't see any evidence of leaking injector (please experts, correct me if I'm wrong).
actual AFT match pretty nicely target AFR.
STFT is from 0.92 to 1.

On the first log, when you lift accel pedal, we can see AFR going up immediately. If one injector was leaking, AFR should take a bit of time to go up

I just noticed some dips in hpfp when shifting, but it may be normal. I don't know


If someone things this logs can show leaking injector, please explain. I really need to understand where.

How would you rate these 2 logs?

One is in 4th https://www.bootmod3.net/log?id=6306...90c624de5241cd

this is 5th https://www.bootmod3.net/log?id=6306...729b57a4e400e1