[designatedposter]

Originally Posted by thejeremyman9

His LTFTs are +14%. So the problem seems to be fundamentally the LTFTs. Basically, he should have ~0% fuel trims, but for some reason LTFTs are going +14, which then makes the car super rich when STFTs are 0 (i.e., on shift, which is normal, as they take a second to respond), then STFTs need to correct by pulling ~15% fuel.

So his STFTs are basically fighting LTFTs, and car is rich when STFTs are not active.

i overlooked the LTFT, it's not a default channel on bm3.

OP, can you do a datalog of cruising at part throttle to see LTFT.

[thejeremyman9]

Originally Posted by designatedposter

i overlooked the LTFT, it's not a default channel on bm3.

OP, can you do a datalog of cruising at part throttle to see LTFT.

Yeah will be interesting to see what they are at cruise. By the looks of the previous log (https://www.bootmod3.net/log?id=6163...0b435691c48861) they seem pretty normal but then spike when he goes WOT. Then SFTFs start basically doing the opposite of LTFTs.

That's why i am wondering if PTF can do a test by just disabling LTFTs entirely and see if the problem goes away.

What i don't see in the log is target AFR, unless i am not recognizing it with BM3 labeling?

[SoCalM235iR]

Further to this discussion about LTFT's, I observed the first screen shot during steady state driving on the freeway. About 1800-2000 RPM in top gear. With very light throttle I took the second screenshot. This is with the latest map from BM3. Clearly, the STFT's are fighting with the LTFT's.

With the stock tune the LTFT's are usually at 0 and never go beyond +/-3.

Also, tested my fuel and it shows no more than 6% ethanol.

I'm planning to put some logs up here later today or tomorrow and then I'm going to to load the BM3 Stage 2 ACN 91 map and see how the adaptions go with the MAF unplugged.

[thejeremyman9]

Originally Posted by SoCalE90

Further to this discussion about LTFT's, I observed the first screen shot during steady state driving on the freeway. About 1800-2000 RPM in top gear. With very light throttle I took the second screenshot. This is with the latest map from BM3. Clearly, the STFT's are fighting with the LTFT's.

With the stock tune the LTFT's are usually at 0 and never go beyond +/-3.

Also, tested my fuel and it shows no more than 6% ethanol.

I'm planning to put some logs up here later today or tomorrow and then I'm going to to load the BM3 Stage 2 ACN 91 map and see how the adaptions go with the MAF unplugged.

Well, at least we seem to be on the right track! Very strange that this would be a software issue when you are using OTS maps, so part of me still wants to think its hardware related and the software is doing what it thinks is right. Unfortunately I don't know enough about how the DME learns LTFTs (i.e., what hardware is used, over what timescales, etc). I am very interested to see what happens when you run without the MAF plugged in and if this affects the LTFTs or your issue.

The screenshot is consistent with your previous logs. LTFTs look normal until you go under load. It's strange because typically LTFTs don't change over such short timescales...

[SoCalM235iR]

Originally Posted by thejeremyman9

...The screenshot is consistent with your previous logs. LTFTs look normal until you go under load. It's strange because typically LTFTs don't change over such short timescales...

The LTFT's move around like the STFT"s are supposed to. Noticed that the first time I ran my gauge app. With the OEM tune the LTFT's behave normally.

[thejeremyman9]

Originally Posted by SoCalE90

The LTFT's move around like the STFT"s are supposed to. Noticed that the first time I ran my gauge app. With the OEM tune the LTFT's behave normally.

Yeah strange... and the fact that the LTFTs behave normal on stock tune... could be software after all. If the MAF test doesn't work i would ask PTF if they can disable LTFTs entirely and test the OTS map with only that change.

[SoCalM235iR]

More logs.

This is the latest custom map from BM3 and I've been running it for about 400 miles, so it's adapted. Same story as before, FP crashes right after Lamba drops to the 11-10 range. I did notice that there are lean events in the 16-18 range prior to these crashes. I believe the system is reacting to those when the FP crashes.

Loaded the Stage 2 ACN 91 map. I'm going to watch the LTFT's and confirm they swing wildly as before and then disconnect the MAF sensor and see if anything changes. After that, I'm loading the stock tune to confirm again nearly 0 LTFT"s.

https://www.bootmod3.net/log?id=616b...729b18ec45e4d9
https://www.bootmod3.net/log?id=616b...729b197d4d5ba0
https://www.bootmod3.net/log?id=616b...90c66fb863c444

[thejeremyman9]

Originally Posted by SoCalE90

More logs.

This is the latest custom map from BM3 and I've been running it for about 400 miles, so it's adapted. Same story as before, FP crashes right after Lamba drops to the 11-10 range. I did notice that there are lean events in the 16-18 range prior to these crashes. I believe the system is reacting to those when the FP crashes.

Loaded the Stage 2 ACN 91 map. I'm going to watch the LTFT's and confirm they swing wildly as before and then disconnect the MAF sensor and see if anything changes. After that, I'm loading the stock tune to confirm again nearly 0 LTFT"s.

https://www.bootmod3.net/log?id=616b...729b18ec45e4d9
https://www.bootmod3.net/log?id=616b...729b197d4d5ba0
https://www.bootmod3.net/log?id=616b...90c66fb863c444

Finally looked at these. Yup, same thing, LTFTs seem OK until you go WOT then they jump to 1.2 and STFTs start fighting them when the car goes rich.

[SoCalM235iR]

Loading a new BM3 supplied tune today. There has been an ah-ha moment on their end, so perhaps this one will address the fuel crashing. I Will report back after adaptations.

[thejeremyman9]

Originally Posted by SoCalE90

Loading a new BM3 supplied tune today. There has been an ah-ha moment on their end, so perhaps this one will address the fuel crashing. I Will report back after adaptations.

Nice, very curious to know what their "ah-ha moment" was! (assuming of course it works)

[SoCalM235iR]

After much work on the part of BM3 support, I finally have a map that maintains acceptable fuel pressure at WOT at all engine speeds and gears, and after adaptations.

While this is not a stage 2 tune, the progress is welcome and once BM3 has reviewed the logs stage 2 tunes with the same adjustments should be forthcoming. I just ran the logs and really haven't spent a lot of time analyzing them.

https://www.bootmod3.net/log?id=6172...0b4322ec1a43e7
https://www.bootmod3.net/log?id=6172...0b4323724786f4
https://www.bootmod3.net/log?id=6172...729b197d4d7230

[SoCalM235iR]

Ran some new logs with the stage 2 OTS 91 ACN tune run with MAF unplugged.

https://www.bootmod3.net/log?id=6178...729b385163cab1
https://www.bootmod3.net/log?id=6178...90c6724ac74f1d
https://www.bootmod3.net/log?id=6178...0b43484cd57fbc

The previous logs show the throttle valve closing to limit fuel requirements during the conditions (RPM, throttle pos, boost, etc) which in previous logs the FP crashed. While this worked okay, the tune significantly limits power with boost capped around 14 psi.

The stage 2 91 ACN tune with the MAF unplugged hits hard without FP issues after 25 miles of adaptations. Logs have about 50 miles. FP drops too much and there are timing corrections, but the dips into lean AFR's during full boost WOT don't seem as severe or as often as the logs with the MAF plugged in.

Will put more time on this tune and post up more logs.

[thejeremyman9]

Originally Posted by SoCalE90

After much work on the part of BM3 support, I finally have a map that maintains acceptable fuel pressure at WOT at all engine speeds and gears, and after adaptations.

While this is not a stage 2 tune, the progress is welcome and once BM3 has reviewed the logs stage 2 tunes with the same adjustments should be forthcoming. I just ran the logs and really haven't spent a lot of time analyzing them.

https://www.bootmod3.net/log?id=6172...0b4322ec1a43e7
https://www.bootmod3.net/log?id=6172...0b4323724786f4
https://www.bootmod3.net/log?id=6172...729b197d4d7230

Catching up here...

Looked at the 2nd log a bit. I still see the same thing as before, where STFTs are fighting LTFTs and the AFR dips (rich) after the shifts, but HPFP isnt crashing, just small dips relative to target. Looks like throttle is also closing significantly on shift and boost target is pretty low which is lowering airflow. You also have a knock.

[thejeremyman9]

Originally Posted by SoCalE90

Ran some new logs with the stage 2 OTS 91 ACN tune run with MAF unplugged.

https://www.bootmod3.net/log?id=6178...729b385163cab1
https://www.bootmod3.net/log?id=6178...90c6724ac74f1d
https://www.bootmod3.net/log?id=6178...0b43484cd57fbc

The previous logs show the throttle valve closing to limit fuel requirements during the conditions (RPM, throttle pos, boost, etc) which in previous logs the FP crashed. While this worked okay, the tune significantly limits power with boost capped around 14 psi.

The stage 2 91 ACN tune with the MAF unplugged hits hard without FP issues after 25 miles of adaptations. Logs have about 50 miles. FP drops too much and there are timing corrections, but the dips into lean AFR's during full boost WOT don't seem as severe or as often as the logs with the MAF plugged in.

Will put more time on this tune and post up more logs.

Looking at these now (2nd log), first thing that jumps out is that timing is very bad - like negative on all cylinders at some points while at WOT.

The interesting thing on the fuel side is that, with the MAF unplugged, STFTs and LTFTs are reversed: LTFTs are slightly negative and STFTs are slightly positive. There are still a few small dips in HPFP pressure but it doesnt look like its for the same reason - no excessively rich AFRs and no high LTFTs driving the excess fuel. This is also a much higher boost level, and there arent really any throttle closures.

Overall, the fuel trim and AFR behavior looks much more typical in the log with the MAF unplugged...

[n55david]

my guy.. you have a mechanical problem with your fuel system. you need to get it fixed and stop having ptf try and bandaid your car.

[SoCalM235iR]

I have tried 4 OTS maps, 3 custom BM3 Support maps and replaced a bunch of hardware and still this car won't run without issues on any of these tunes.

Without the MAF input does the computer run off speed- density maps with AFR feedback from the O2? What range does the MAF swing AFR's? I want to log the stock map and see what the LTFT and STFT's do with/without the MAF

[SoCalM235iR]

Originally Posted by Phantom10R

my guy.. you have a mechanical problem with your fuel system. you need to get it fixed and stop having ptf try and bandaid your car.

100% of the fuel system has been replaced. Thanks for your helpful contribution.

[thejeremyman9]

Originally Posted by Phantom10R

my guy.. you have a mechanical problem with your fuel system. you need to get it fixed and stop having ptf try and bandaid your car.

I was saying the same thing earlier on, but all evidence and testing suggests its not a hardware issue. Even PTF has pretty much admitted that. The fuel trims are fundamentally the problem.

Originally Posted by SoCalE90

I have tried 4 OTS maps, 3 custom BM3 Support maps and replaced a bunch of hardware and still this car won't run without issues on any of these tunes.

Without the MAF input does the computer run off speed- density maps with AFR feedback from the O2? What range does the MAF swing AFR's? I want to log the stock map and see what the LTFT and STFT's do with/without the MAF

Can't say for sure, but I believe so. I almost going to say try MHD as an experiment lol... You can always resell BM3 right?

But yeah testing stock map again to look at logs might be informative.

[n55david]

Originally Posted by SoCalE90

100% of the fuel system has been replaced. Thanks for your helpful contribution.

100% guarantee you have a problem somewhere.

[SoCalM235iR]

The easy answer is yes, there is a hardware problem with the car. However, there are zero issues with the stock tune or when I ran a JB4.

All the typical N55 problem areas have been addressed, coils, plugs, sensors, both fuel pumps, all 6 injectors, O2 sensor. The only failed component during the "shotgun" repairs was one FI slightly leaking. What could be failed/failing and not throw a code or be obvious?

The Fuel Trims behave erratically with the PTF tunes and the adaptations seem to swing the AFR's and ultimately crash the fuel system after some miles.

I've considered trying MHD, but BM3 was my preferred platform and clearly, these tunes should work fine for me like do for so many.

[thejeremyman9]

Originally Posted by SoCalE90

The easy answer is yes, there is a hardware problem with the car. However, there are zero issues with the stock tune or when I ran a JB4.

All the typical N55 problem areas have been addressed, coils, plugs, sensors, both fuel pumps, all 6 injectors, O2 sensor. The only failed component during the "shotgun" repairs was one FI slightly leaking. What could be failed/failing and not throw a code or be obvious?

The Fuel Trims behave erratically with the PTF tunes and the adaptations seem to swing the AFR's and ultimately crash the fuel system after some miles.

I've considered trying MHD, but BM3 was my preferred platform and clearly, these tunes should work fine for me like do for so many.

Running with the MAF unplugged seemed to prevent the issue, right? Have you cleaned the MAF or considered replacing?

[SoCalM235iR]

Originally Posted by thejeremyman9

Running with the MAF unplugged seemed to prevent the issue, right? Have you cleaned the MAF or considered replacing?

I've cleaned the MAF a few times, and I would think that the OEM tune would have a similar issue if that MAF was faulty. I'm not convinced that unplugging it has completely eliminated the fighting fuel trims.

I have switched to another tune on the advice of support and will log that one with the MAF unplugged and we'll see if that makes a difference. I will post those logs as well.

I'm looking again for leaks somewhere between the air cleaner and the turbo inlet, perhaps allowing unmetered air into the intake. Hard to believe that wouldn't be a full-time problem if it was happening but checking regardless.