Findings and conclutions about misfires and ignition pulls

[135boost]

Hi

I started this cause there seems to be numerous different approach about this stupid and very annoying issue of n54 misfires

I think half of those is just related to worn out parts like stock coil, plugs, faulty injector or just clogged intake runner, piston ring land, or something else very obvious.
But then there seems to be a bunch of misfire issues not covered by those common easy fix and owners has throwed and swapped every part in whole engine department and still struggle with this issue.

First this engine is still just a petrol burner, air, fuel, squeez, bang, exhaust dump..
I have struggled with these for few years now and still miss the root cause for them. Trebila has been awesome help and p33p33 even more awesome help to tune this but still there is to much on the dark side of this issue, and for sure, i'm not the only one with this. This seems to be stupidly sensitive to all what can cause misfires.

At the end of day, solutions should not be in a level of "edge where maybe it ignite every pulse", more like enough room for to be sure we aren't even close to misfires, damn, gtr's with these miniatyre plugs iginite even with 55psi and 2000 horsepower and propably 40% more cylinder pressure at the moment of ignition without issues.

What i have read from these forums, numerous injector swaps, numerous playing with different coil packs, spark gap, finetuning of software, different plugs, wichcraft, gremlings, different brand of fuels etc and still misfires even with big players like Tony @ vtt, Terry @ burgertuning and numerous others too.

Damn it, even 1970 made carburator engine turbocharged ignite mixture without issues so why is this so damn difficult.

First known real issue, miniatyre size spark plugs what for sure is more prone to run to issues cause of very thin layer of insulator and frame been close to electrode, that is somethinw what just is, caused on limited space in combustion chamber in di engines.

Then few things about di and plug relation what can trig issues, injector is very close to spark plug and with very high horsepower n54, on di, when injection window start (not sure about excact timing cause of missing map in xdf but some guess is that window is some 250 degree ) piston is close to tdc and maybe there is on big injection quantitys in that situation to some degree of risk to wet the plug.

First question, have there been any notices of difference in full di to the max with bigger di hfpf systems versus di plus pi cause on that occation, di plus pi should be less prone to this if that is the case

Second question, b58 style spark plug with much more protected center electrode could also provide some protection against that wet foul possibilities, some notices if that does any positive effect against misfires. Someone maybe even tryed pi only?

Seems that pr coils, b58 coils etc has for sure enough energy to ignite this kind of combustion so i think we all can be sure it's nothing to do with pure spark energy. Energy need is also reduced with spark gap reducing even if combustion pressure increase energy need and spark resistance at level of 1 to 1

What about mosfets or cabling to coils, i don't think cabling are too small to proper support coil charge even if they ain't ment to support more than stock coils but what about mosfets ability to disspatch heat with much longer dwell times in optimated dwell maps? I really think we have enough knowledge on those proper optimum coil dwell tables to rule out thatwrong chargetimes from issue causings list.

There has been one test what i have found from web where those was measured and conclution was that b58 coil is superior to allmost everything what can be throwed in in dumb coil markets. Has there been any taughts on temperature issue or is there real differences when used smart r8 coils on misfire front?

What about heat sink glued with thermal glue on top of all mosfets? Not so very difficult task to do.

On mechanical side there has been reported that some teflon tape wrap to injector has cured a small amount of misfire issues, sounds like bush fix, it may work but not caused of better sealing to combustion, it should worse out that sealing situation caused by many time bigger area to be sealed than that orginal 8mm but there is one thing what on my opinion has been totally missed and what that teflon tape could on short term cure.

What if the issue on that is not gas leakage, but jiggering of whole injector as a result of combustion chamber high pressure pulses?

Seems to be that issue is escalating with boost pressures over 25 psi and that teflon wrap fix has been when there has been complains about injector bore been out of shape or loose.

I came to stupid taught, what if that big cylinder pressure is starting to resonate the whole injector against the injector holding clip, that could easily explain wear out injector hole, that for sure could cause very erratic injector behavings caused on movements inside of injector and it's needle. Area of injector is in size of 0.5cm2 (8mm cross section ) at injector injecton nose where that teflon seal sits so if there is some 100bar cylinder pressure at highest point, the spring has to be hold some 50kg force and i'm sure it does not withstand that without some warping or small resonation. What if the injector locking spring is orginally designed to work as some kind of hydrolock protector to give up after example double orginal cylinder pressure and designed to protect pistons and stock rods in a case of injector fairlure and pump combustion chamber full of gasoline? And then when we reach that level with double absolute charge pressure, what is in a level of prox 40psi compared to stock some 20psi abs, 14,7psi plus some 7 or 8 psi boost? Just playing with idea...like valve float, difficult to show out as small amount until it's sewere issue an can be heard.

On these n54, that resonating frequency is in a rateof 2500 to 4000hz, half of engine rpm so monitoring should on my opinion be done with high speed videocamera in a dyno under full pulls to se if there is a issue. That spring type injector holder is not to be seen in any diesels, tfsi, n55, b58 or other engine models so what if this is the real issue in these n54's and was at the beginning a idea of bmw engineers to do it as that mentioned protector cause it was their first di engine?
I think movement level to mesh up injector is in a level of 1mm or something so movement does not have to be even visible to eye without slow motion diagnostic video.

Easy fix for sure is stack 2 springs to clamp that injectors, doubling it's clamping force. Has anyone even tryed that?
I have a spare of those and for sure will throw them in to do road test to it but i don't have easy access to chassis dyno or high speed camera equipments to do real investigatios other than road tests.

On afr side to solve this issue, it seems to be regardless of afr, for sure very rich mixture is causing misfires but even of correct best power level afr or little on lean side of it, it seems to be a issue still having mystery misfires.

Next question, if that is dme related, then all with syvecs s6 or s7 should be without any misfire issue at all, is that the situation? If it is, then dig again us in to dme mosfets.

In some occations, there seems to be claims that weak battery is causing these kind of issues but
That should stress more generator than trig misfires if dme feed voltage stays on decent level.

For sure i know this is a network of different bus in these so maybe there is some relations caused of some mystery module like lfpf but i think it's long shot.


My setup starts to run to misfires in a region of prox 23-25 psi, tested 3 different injector packs, 3 different coil packs, both pr and n58 coil packs, slight different afr's, diferent plug gaps, different dwell table values, even p33p33 knowledge, and misfire is popping up somewhere in 6000-7100rpm at every pull with at least one gear recovered after second or two to normal again and to the point of misfire everything seems to be totally normal except ignition pulls
Propably related to some torque limit table, 6at (testing at the moment on 29psi and target at the end is 33psi with 1:1 boost exhaust pressure) what i think is a totally other issue.

That ignition pulls has been reported that is more prone on xi models, and if so, it can be related to noise from dront diff ve rwd cars, more than diferent in calibrations or something else, faulty prop shaft or half shafts can bring noise to oil pan what can trig it but on mine, i tested few pulls with knock deactivated at over 3500rpm and still puls so it's not knock in my situation.

Known trigger increaser is forged internals, check, high lift cams, check, closed deck, check, xi, check, so i have them all.


Taughts?, suggestions to keep my mouth shot? Ideas ? And yes, again, i know my english is not perfect so gramma lections suggestions don't belong here eather or could it be better to write on my natives Finnish or Swedish

 

[135boost]

those injector values is to be found on inpa too but individual knock values are not as that true dwell.

about that maf tupidly close to 400, for sure other tweaks in tune is changing that calc value too so if it`s that what there is something trig that misfire, it`s not straight maf but something relating maf close to 400.

depending on boost between 20 and 27, it seems that every time i close to 400 maf, it misfires and recover somewhere in 440 maf.

there can be some maf related thing what goes over some value or jump to some next cell in some stupid safety mode
what cause this.

checked some older tunes with very different maf changing parameters and there misfire trig happends at 370 maf +-5 at every time and with this seems that little depend on parameter changes, it is now at CALC value of 400.

if it hit some safety wall, why does it recover after some time, it seems to be time dependent too, every misfire gap is timebased in same lenght, maybe some similair that on ignition advance, when acc, it jump to spool but it keep it on spool only limited time, then back to main, back to spool etc.

that can be one interesting place to dig, maybe 3 sec at "maf 400, then reduce torc to 1 sec, jump back to chart and lookout if there is still conditions for torque reducing but it hit rev limiter or gear change before it trigs again.

ps. i will check that bimmerlink too..

 

[135boost]

when i started this topic, it was more than just solve my misfire issue, and this has evolved to colletion of ideas to resolve issue to real root cause.

one more than interesting find about misfires except that what i did discover about close to calculated 400 maf g/s
is that when i did go trough some 40-50 logs with the issue excisting, time what misfire last if misfire detection is off is 0.8 second in every single one of those, rpm vary, boost vary, and because of tune differences, load and maf vary a bit but that 0.8 second stays on every single misfire what i found in my logs.

i had now done pulls to 7600-7800 levels with misfire detection off and misfire is occuring in range of 5400-6700 rpm depending on at most of boost but other tune factor seems to do small canges in rpm range.

that must mean on my opinion that it must be tune related and not hardware related issue.
like i wrote before, small variances in maf mean that it`s not straight maf g/s what trigs this but some other calc value
close to that point what (my guess) is reduce torque on some basis just like that ignition advance play on ignition when on spool mode, jump to main table time based on some logic and back to spool/main/correction factor and easy way to reduce torque is to blackout one cylinder (6) for 0.8 sec and reignite it, and seems that next blackouted cylinder is in my engine cylinder 2 if both bank has that blackouts, and again, 0,8 sec.

my skills is not enough to dig in bin with winols (yet ) nor skills to do fuel density map to tunerpro or build
mhd logging parameters what to log but i`m more than happy to try resolve things like this test based.

on my bin there is
disable tq safety path
disable tq safety path soft
disable tq safety path hard
disable msr interventions
disable asr interventions

all is set to 01 ( some was 02 for some reson
******************************
ps. just digged me to single cylinder cut off in FR and there is bunch of different things that can do just this kind of single cylinder cut offs and learned a bunch of things.

on torque based torque reduction, philosophy is first to try to reduce ignition advance and afr and if that is not enough, then cylinder cut off (why do we have ignition pulls and then misfires ?? )

that spark retard phase seems to be at least time dependent because of limit to avoid extreme exhaust gas temp and therefore next step must be fuel cut off in single cylinder (sidenote, nox cat protection mode in my bin is 2700F)

all these should be seen in LV_AUTH_TQ_PATH and if it`s based on torque TQ_REQ_FAST and TQI_REF corrected with AFR and ign angle, it calculate EFF_SCC_SP setpoint what lead to NR_PAT_SCC

those lead to parameter where there is max retard point and earliest fuel cut off point.
there is too that hysteresis to cylinder cut off what can explain that 0.8 sec window.

EFF_SCC_BAS single cyl cutoff is for faulty injector, not considered at this state

single cylinder cut off authorisation flag
LV_TQ_SCC_ENA_MAN (what usage ? )
LV_ASR_ACT ( hope this is deact with that value 01 )
LV_GS_ACT gearshift softening, (this is ok)
LV_N_MAX rpm limiter, (this is under control, ok)
LV_FCUT_FAST ( hope this is deactivated with 01)
LV_TQ_SCC_REQ torque management
LV_TQ_SCC_INH torque management
LV_TQ_LIM_INTV safety concept torque limitation

there is note that most of those can be inhibited EXCEPT SAFETY AND TORQUE BASED ones.

LV_FCUT_FAST seems to be more on deceleration situations but what does it do to this wot ?


B_ZYLAB_1 logical value for cutted cylinder in bank 1
B_ZYLAB_2 logical value for cutted cylinder in bank 1

these can explain why it`s some particulate cylinder like 2 and 6 in my engine

there is restart fuel feed too what also can explain that odd 0.8 sec window

ASR interventions is safety AntiRoll things, hope that 01 is deactivate that
MSR interventions is more traction and skidding thing, hope 01 is deactivate that

so at the end what left was some torque limitation based issues that can not be solved due ignition pulls or some calculated exhaust gas temp is rising to a value where time frame window is kick in and what i got too from that is the next step is fuel cut off in pre determined cylinders, and seems that all who have misfires has first ignition pulls so maybe this is leading to deactivate some fuel torque based fuel cut off module tests or if not else, because of "not possible to deactivate module" at least short that 0.8 second window close to 0.02 second what is resolution for these


playground is yours, opinions, suggestions, skills to do some tunerpro toggles, mhd loggers or something

Hope to solve out this to th ground before moving to the dark side...one year to my plaid x arriving...

************************

datazap.me | Maantec | Log 1636997644

datazap.me

New log, new test, max knock retard is set to 0 and still retard so demand of that is not knock.
Then next notice, if it spool rpm fast enough, it won't misfire.
Third notice, not so vice way to try ful boost at wet surface, some small wheel spin..... rewwed to 7800.

So, i tested this 3 times, not any misfire if it spin wheels and time to spool revs is short enough.
It must be some safety torque reducing using first ignition retard and then timebased single cylinder cut offs..

 

[135boost]

One stupid idea, i think there is 2 major aproach for tuning these n54 engines, jb4 at easy low level stage tune and then trough bin with mhd.

I think extremists all turn to mhd and and on mhd tuners, we need more mo itoring parameters what mhd offer to dig out root causes for these kind of extreme type of issues.

Most of those logging is vital to find problems and half need toggle 0/1 and half then some maps.
Toggles is vital to have a way to see in witch state of logic path there is some logic demand of ignition pull, single cylinder cut off, torque limit demand or something like that.

What if we could try to add maps in to xdf and add loggings to mhd.

Carabuser did outstanding job already to add to my mhd possibility to log true dwell angle and i found out
With that issue when i had 3.200 dwell, after all logic step, true dwell was only 2.100.

What come to my mind is
Knock voltage to all cylinders
0/1 toggles if there is
-knock activated on any reason
-ignition pull reason
-safety logic activated
-calc nox exhaust temp related reducing


Eoi
Soi

On mhd we have torque limit act parameter but i don't know if that show all torque related decrease or limit issues.
We have too fuel side spool or main mode visible but on ignition there is differ logic path, not visible.

What else could be usable information

 

[carabuser]

Toggles are all in the BIN, you can't log the state of a toggle since it's in ROM not RAM. You can log the RAM values either side of the toggle to see what path is active but the best approach is to look at the toggle address in your BIN and see if it's set to 0 or 1. In the logic diagrams the toggles are depicted as showing the path of the toggle when set to 0.

I've logged a lot of different RAM addresses while troubleshooting issues and the only ones that I keep are the torque limiter channels and the modelled torque values that are sent to the DME as the one that MHD logs is not really important for shifts. MHD torque limiter channel is useless, the DME has two torque limiting paths, fast and slow, MHD only logs a combine signal so it misses some limiters.

Here's an updated logging file with the two limiter paths added and all 18 injection values. I've also included the PDF that details what the torque limit values mean.

 

[carabuser]

The injection values are experimental. I'm not 100% sure if those are the right addresses as the logic is tricky but it should be pretty apparent once you start logging if they are right or not. I would expect the first phase injection value of each cylinder to be very similar, the only variance would be the injector calibration values and some adaptation values.

This should give you an idea of how much fuel is being injected and how the DME is spreading it across the 3 injection windows.
On the higher powered N54 engines BMW did make changes to the injection distribution so it could be that there's gains to be had from tweaking the fuel distribution.

 

[135boost]

Hi again carabuser.

I tested those injection values and they are close to right, at least MHD log them, i think they only need small adjustments and they are spot on.

Cylinder orders compared to phases are on my opinion wrong as now there is cyl1 phase 1,2 and 3 then cyl2 phase 1,2,3 etc and i think it should goes like bank 1 cyl 1,2 and 3 phase1, then bank1 cyk 1,2, and 3 phase2 ans at last bank 1 cyl 1,2 and 3 phase 3.

On my test pull , it first at idle drive equal all 3 phases, then it start to reduce first quantity from second phase ( cyl2 in that log, think it`s cyl 1 phase 2) and then at combined 120mg/hub value it drop phase 3 out (in that log cyl 3, think it`s cyl 1 phase 3)

At combined all tree phases with 190mg/hub it drop phase 2 away too, ( that log cyl 2) and continue with only 1 phase (cyl 1, think it`s phase one in cyl 1)

So to simplify this, it drop to 2 phase at 120mg and one phase at 190mg.

Disclaimer, i hope i guessed and wroted phases right

Those stupidly high fuel scalars is caused by reduce of injection quantity at that second phase and it correct the situation just as it hit combined 120mg level and one (third) phase drop off .

I got misfire again, like always before at 6300, and again that is close to 400 maf (420) and before misfire, it has ignition pulls and againthat same patter with 0.8 sec and at that point phase 1 injection quantity was at single injection mode at 247mg/hub level.


Calculated from this, my max mg demand goes at least to some 270, hope these injector and dme support it.
To remember, i has one additional injector at 1200cc to inject straight to chargepiepe too and that can mess something by small amount but injection start well beyond 3800rpm so that 1900-2700 gap high scalars is not affected on that.

Does those values sound right?

Then, slow and fast torque path limiters shows value 0 whole time as do torque limit act too.
Fuel mode goes to 15 cause of open loop, that's all.

it may be stupid comment but in my eyes that how injector phases work looks pretty close like stratified injection with are activ in some window between maybe 1500-3000 depending on tune where could be that reason for 3 phases, it`s to run stratified, like level based ( different afr in different height of cylinder fill, it start with rich injection when piston is start it`s journey down in intake sequence, then second phase lean and again last rich so when it`s compressed, there is richer afd close to spark plug to iginite easier, then lean center part and again richer close to piston to eliminate knock, that level mess is for sure messed with cams and vanos and ported head etc but could be the case) cylinder fill injection in to cylinder and that maybe is reason for that hill in fuel scalar at those rpm`s.

datazap.me | Maantec | Log 1637515093

datazap.me

check this, sorry that there is cyl 6 and not cyl 3 but i think logic and fuel injection mass is quite same

 

[RSL]

Those addresses are partly off. For other roms, there are no distribution factors that I saw for split over 2000rpm in triple injection (yours may be 2500) or over 4250rpm in double. Yours are in those ranges, but are obviously not correct by injector # since 2 and 6 show 0 fuel for any WOT >4250rpm.

N54 doesn't run stratified or HS and even if they did, they'd switch to homo at load increase, boost or rpm limit.

If you want to reduce scalars, you've got 2 basic options: tell the DME there's more air coming in so it calculates more base fuel using the stock calibration/functions or increase the requested fuel mass per air mass calc directly. You may already be at/over of what you can get though.

Fuel mode 15 is likely causing that misfire. It goes open loop and misfires. Part or all of this may be your boost and scalars/AFR target. I haven't looked at this much, but 1389 mg/stk is every mass value limit I've seen and 1389/6 = 231.5 mg/stk per cyl. There may be some wiggle room in reality, but unless I'm way off base, you may just have to consider that you're already asking for too much since it's in excess of 240 and that's when the problems start. There are bankwise mass calcs too, so it may be a problem primarily generated from bank 1, but it creates a problem overall.

I think you have 3 options/combos to try: back off boost, keep the boost and try running leaner or add more supplemental fuel and back off the load DI injectors are calculated to carry. The goal would be to drop calc fuel mass <230 and see if the emergency mode/misfire stop.

 

[135boost]

You RSL opened whole new page in this kind of misfire dicussing issues, that 231.5 mg/stroke limit can be the cause of whole misfire issues in these engines, that could explain wierd high power single turbo di only engine misfire issues.
that 231.5 could explain that 400g/s maf limit too because it seems to be the limit where that issue strikes, little depending on afr targets.
that could explain too that this does not trig any torque based limit ( fast, slow torque path lim), just
open loop and misfires

i think that wobble from 231.5 to 247 what you mentioned is caused just by by some timeframe.

about homo, strat or hs modes, my opinion is that it runs some kind of hs mode and you have it absolutely right
that it move to single homo mode when load increase, that explains "second phase" quantity drop ( we agree that cylinder # are off but like carabuser told, there can be errors and he was not 100% sure about that logic.

This mean that this engine is limited to some 700hp/800nm DI only mode without additional fuel using E85.
rest is dyno scaling differences, dyno number inflatings, AFR target differences etc, there just is not enough fuel.

question, there is no way to increase that 1389mg mass value to some more decent 1700?

to get low rpm scalars down, i think the best way is to increase that second injection phase quantity
(what i think is strat/hs mode) byt i can live with this scalars run to -10% and engine runs flawless.

real issue seems to be that high rpm 231.5mg/stroke

my real fuel need at the moment is somewhere in 280 mg/stk and i think it run to 300+ when i have full 30psi+ boost so leaning out that much or back up boost by 10psi is not either a option.

that is easy to test,i just increase that injector size in chargepipe by 50% and see what happend. that add additional fuel quantity to some 1700-2000cc and that still fit scalars.
if that solve this issue, seems that i need PI adding to this, that was what i tryed to avoid at first because risks if injctor fails and compexivity (hahaha, tell about hundreds of hours complexivity tuning learning path).

 

[135boost]

To continue discussion, there must be logic behind all this that fuel scalars affect only first and third phase and leave that second untouched or then scale it to all 3 of those with different scale, my guess go to only 1, main injection.

There is in my xdf a parameter to force this to single injection mode from start to whole rpm range, did test that once but it screwed fuel injection mass so badly that i turned it back to 3phase.

That single injection mode for sure proper scaled will fix cruise speed very high scalar values. Thanks for that discovery goes to p22p33

 

[carabuser]

I'll change the order of those injection values. I knew they were the right RAM area, just didn't know the order exactly as the logic writes to an array and calls the routine once for each cylinder.

The scalar is applied before these individual injection phase values are created.

The rough order of events is that the actual engine load values is taken, then multiplied for corrections like fuel scalar, spool, warmup and a load of other fairly insignificant values then it's divided into 3 paths depending on what your injection tables are set to, then those 3 individual values are multiplied by a constant to convert them into fuel mass rather than engine load. I posted the address for that fuel mass constant in the E85 discussion.

The engine should always be in homogenous mode. Never homogenous stratified or stratified.

 

[135boost]

That 3 phase logic

 

[135boost]

“We choose to tune bmw n54 in this insanity and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one ... so.. is it even technically possible to increase that 1389 value or is only path port injection

 

[RSL]

The conversion would need to be changed in the program. If it had to be all masses, it would be a lot of work and may negatively effect things we've not even thought of yet. We'd need to dig in docs and you should test anyway since it's just a theory right now. If you're comfortable leaning it out, I'd start with that.

People have misfires without 15 at high rpm on big boost all the time though. This might just be part of it, but would add room to what DI fuel system could do without PI if it worked.

Depending on the rest of the tune, simple things like vanos and other factors that effect air/fuel calc will move trims up and down. There are a lot of moving parts requesting high load/going into boost, especially at low rpm. I'd suspect the rise and then drop is either vanos or a blender on something.

 

[wheela]

“We choose to tune bmw n54 in this insanity and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one ... so.. is it even technically possible to increase that 1389 value or is only path port injection

Sorry, I'm on my phone and I think I may have somehow accidentally clicked this as the solution, but I'm not sure and don't know how to un-click it if I did (insert face palm imogee here...)

 

[135boost]

so, i continue and like RSL suggested, will test it with little leaner AFR, it`s now at prox 11.7-12.0 and i can go "comfort" to some 12.6-12.8

that should buy some 8% headroom (250x.92=230) and them i can put some 200cc ( i have that size stock) bigger additional injector
to chargepipe so maybe close to 10% fuel mass difference show some changes or at least move that MAF 400 some 105 to some direction.
about fuel

517

that K_UFAK_RKMK, is that something to try move goal poles ? did it solve something ??
how do i get in to my Tunerpro?

it`s more handy when i get new log with corrected cylinder numbering tables from carabuser to log these, they look easier to read

**************************

So, we got snow here few days ago, make log pulls little more tricky ..
installed little bigger additional injector to chargepipe and leaned out afr by small amount, 0.5
to be on safe side.

first dry day so i will pull a log or two to see if the issue is that 231.5 mg/stk
it can be that i have to play little with scalars too to get calculated fuel mass
lower.

i still miss that K_UFAK_RKMK from my xdf, that, if i got it right should move fuel mass calc because it
should change fuel weight to volume or energy density and if that 231.5mg/stroke is weight scaled, maybe
thet will move calculation to right direction.

 

[KClemente]

I can verify that k_ufak_rkmk will change injection quantity and tested it very briefly back when I was running full E85. Added 30% more and trims went down aprox. 30%.

Haven't tested it past idle speed though.

 

[135boost]

So you reduced ( told that added )30% to k_ufak_rkmk and it increased injected quantity of fuel by 30% and therefore reduced trims by 30%.

************************************
ok, right direction is then to increase value.
i had in my bin value 45.690, assume that is stock value?
so 30% to that value is prox 60 and that should be compensated with dividing
whole fuel scalars by 1.3.

if that work, then i have my scalars down to some decent 1.15-1.40


If there is xdf of that to share, i'm more than happy to get it

 

[KClemente]

What rom version do you have?

Yes the right direction would be to increase the value, but it is still very much so untested past idle speed. No one knows yet what will happen under load

 

[135boost]

So, we got little snow and -12 to -18c weather here so no test pulls.
I ordered port injection kit with split second controller to more precise
Feed additional fuel to engine so for sure there is a way if there is a will to solve out
That problem if it come from that fuel limits.

I will test that k_ufak_rkrm too when i get my intake on the place again but next week seems to
Be in level of -15c forecasts..

 

[135boost]

so, half year has gone again, huge problems to get ordered a PI standalone kit, took half year to get one :-(
first ordered it from deutchland to avoid messes with customs, payed and waited to get it, estimating was 1-2 week..
.. 3 month later after many time trying to contact them i was pissed enough, took contact to paypal to recollect my money..

then next attempt from texas, again 1-2 week delivery estimating, same thing, 3 month without any answears to anything and
again recollect my money trough paypal.

third try from england, same splitsecond and PI kit, promises to deliver in a week and indeed, got it in a week with superfine customer care too.

got it installed few weeks ago and tested if that mysterious cylunder blackout has gone, nada, it`s still existing.

there was some toughts that in a bin there is some fuel injection mass limit to 234.5mg/ stroke and when pass that it start to
jerk with some cylinder fuel cut off in a sequence of first 5 or 6, something from bank 2 anf then something from bank 1 and my
fuel injection masses was from ecu in league of 240mg/stroke and then additional fule as rest.

now with this PI i dropped that DI mass to 210 ( 6x750cc so i have room to drop it even more) but issue is still exist so it`s not
that 234.5 mg limit what cause this kind of issue.

history repeat
-it start very close always on sam rpm with same tune
-to trig it, it need about 4 sec wot with boost
-cylinder individual cutoff last always 0.8 sec
-it start always from bank 2
-if continued flooring, it cut off one cyl from bank 1
-after recovery it work prox 2 sec before that sequence start over with first cutoff in bank 2, then possible bank 1
-i didn`t notice it to happend under 21psi boost
-with 25psi it is in little higher rpm rate, maybe 6000 and with 29psi it trigs at 5600rpm so about same amount of calculated airflow


my opinion is that it`s still some limit value what is monitored for that prox 4 sec and after time passed and limit is over, logic
command to shut 1 cylinder to reduce some value, then if it`s reduced enough, it recover after that 0.8 sec, if not it shutoff another cylinder
from another bank, and again 0.8sec

after that sequence it recover and monitor that limit value maybe 2 sec and if limit is over, it start that same limiting sequence again.

i have done so many part changes to rule out bad injector or coil or plug and done many leak test and
compression tests to rule out those issues too so i`m very sure it`s DME related issue.
it`s much possible that there is even no found hidden table what limits this but some table should even recalibrate something so much to
wrong values that it does not hit limit that maybe hidden value..

from DME i have done various tests and i`m very aware that i take risks with my engine and transmission when doing these tests
but after numerous tests and even with help from carabuser and p33p33 no real solution and i start to run out of options.


-knock off
-ingition retard off
-traction control off
-misfire detection off
-etc

now testing
-torque loss tables recalibratings ( they should be untouchable but just try to do something to fix this issue)
-max torque at clutch (this has very odd scaling in tunerpro )
- other various values.


ps. at least it is now confirmed that this N54 engine USES HOMO, STRATIFIED and HOMO+STRATIFIED modes
against all internet informations and this is reason for lean running area and high scalars in fuel tables.

it idles and run with HOMO in all situations under prox 30mg/stroke and return to single injection mode latest at some 170mg/stroke
and between those values it run 2 and 3 phase injection with ofen leaner center injection phase.

pps. any other ideas to try, i don`t have skills enough to use winols and dig maps out to monitor from there in MHD so
there is a place to help