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Thread: Misfiring issue

  1. #26
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    Edit: please disregard what I said about the stuttering being gone: it's not. I have had a few tens of miles trouble free but it's back...

    An additional piece of info while I'm at it: I noticed on a few -
    rare- occasions that the car would rev a bit by itself when close to idle rpm

    So here is an update on the situation. To make it easier and avoid reading the whole post again, everything that one needs to know is written here.
    Basically I'm back where things have started a few months ago (unstable idle when coming to a stop from high speeds, to the point where the car sometimes stall) but with a few things that have been done and should therefore be out of the way:

    - after fixing the fuel tank leak, the remainder of the stuttering has gone. The only remaining "symptom" is that once every 3 or 4 hard accelerations, the car seems to hesistate/run a bit out of breathe at high revs (past 4500rpm)
    - icv has been cleaned twice
    - DISA has been checked twice and works fine
    - all hoses to MAF sensor and between MAF and intake manifold have been checked and are fine
    - after clearing the 10 error codes shown previously and running a new diagnostic with INPA, here are the codes I'm getting:
    * n°125: "avtivate electric fun" (WTF can that mean? )
    * n°56: "signal ignition current measuring resistor"
    * n°246: "throughput rate secundary air system to low bank 2"
    * n°45: same as 246 with low bank 1

    Based on all that I believed that there are two possible causes to that:
    - I have a MAF issue: either it's soft failing and has a hard time reading high air flow inputs and/or transitiond between high and low air flows (consistent with high/slow speeds) OR, being a stock 323i MAF, with a smaller diameter than the one that normally comes with the 330i's intake manifold mounted on my M52TUB28, it just can't cope with the higher airflow and somehow skews readings.
    - There is a vacuum leak which means that I'll have to remove the intake manifold to look for it, given that every other thing has been checked. Smoke testing won't be possible because there is just no way I can get my hands on one.

    I'm leaning towards the MAF being to small, especially given that the issue appeared immediately after flashing the DME with the M52TUB28's software, but I could be wrong. Given that, depending on the issue, I'll have to spend either a significant sum on a MAF or put a lot of time on the IM, I would appreciate the input of the experienced people here before doing anything.

    P.S.1: I think the last two errors are due to the SAP delete.
    P.S.2: I'm not getting an SES light.
    Last edited by Breeze1; 11-04-2018 at 12:54 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  2. #27
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    Pause. No this is not a maf size issue, and tinkering with that will only introduce more variables. You have not oversaturated your current MAF.

    MAF signal code 8, error frequency of 40 times. Start there. MAF or wiring fault caused 40 losses of MAF signal.

    You also had some oxygen sensor loss of signal codes. Frequency of 2 and 5.



    Your ecu expects secondary air pump, but you don't have it. Minor error. Fix later, it isn't causing your issues.
    -Abel

    - E36 328is ~210-220whp: Lots of Mods.
    - 2000 Z3: Many Mods.
    - 2003 VW Jetta TDI Manual 47-50mpg
    - 1999 S52 Estoril M Coupe
    - 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
    - 2019 M2 Competition, self-tuned, 504whp
    - 2016 Mini Cooper S

  3. #28
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    Okay so I'm running out of ideas and patience here...

    Today I checked all the ground wires (the 3 on the coils, the big one below the ac compressor, the negative battery cable that needs to be bolted to the body in the trunk), which are all fine, AND I was very happy to find out that there was a hose on the rear/right side of the intake manifold that was simply not put in place.

    So I thought "boom, there is the culprit that has been causing all the stuttering", put it back in place, put a rubber cap where the small vacuum hose that used to go to the SAP were.
    All seemed well: very smooth idle, it even got rid of some kind of resonance I used to hear near the exhaust manifold from the day the engine was swapped, to the point where I thought it was normal.

    But I still have the stuttering issue! It even seems to have gotten worse than before putting that hose back in place.

    Here is how the car behavior breaks down:
    1) no stuttering at all: when it's like that it runs smoother and stronger than it used to before the issue appeared. Climbs all the way to redline without ever running out of breath

    2) no stuttering per se, but the acceleration is clearly not as good as in 1). It's like it's "softly" choking past 3000/4000 rpm

    3) stuttering: if I press the gas pedal anything more than VERY lightly, it starts stuttering. It occurs randomly but it also seems to occur often upon upshifting after going through 2).

    I have no MAF error codes or anything vacuum/fuel leak related. The only codes I'm left with are 56 (which my electrician thinks is related to the SAP delete, the SAP's connector, which is unplugged, having a brown wire among the 3 wires it has in total. 45 and 246: clearly SAP related. Please look post above for the codes meanings.

    I feel like I'm chasing a ghost and can't enjoy my car anymore...

    P.S.: my question might seem stupid, but let's pretend there was a vacuum leak/unmetered air entry, which is gone. Is there any procedure that should be followed to "bleed" the system from any air "bubbles" or whatnot?
    Last edited by Breeze1; 11-06-2018 at 04:39 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  4. #29
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    *MauiM3mania: please kindly rename the post "Misfiring issue", as it will better reflect the content of the post, and I couldn't change it myself.

    So here are the steps that have been taken so far to solve the misfiring issue, unsuccesfully:

    - solved intake leaks
    - solved exhaust manifold leaks. Today we removed the front EM to check the gasket and make sure it was fine, tightened a few bolts, tightened the bolts on the back EM as the gasket seemed fine. There are no leaks anymore but what is confusing us is that there still is a sound that could be coming from a leak. Given that both EM are perfectly flush with the motor, the only thing we could think about is that there is some "echo" coming from one or both of the cats. Basically all bolts, gaskets, you name it have been checked and there is no leak... other possibility I can think of is that the excess of air provided by the CAI filter and the M54's IM somehow create that echo inside the EM. For reference, the sound coming from the stock M54B30 catback is noticebly louder than on a stock 328i indicating in my opinion, a higher airflow.

    - made sure that all spark plugs are tightened properly: they are (new platinum 4 which I'll replace following your advice Chris, but I can't find the OM NGK - BR6EQUP... something" ref so far. There is a brownish dust on them, I don't know if it means anything...

    - checked coils: they look "brand new" and are original Bmw's. No cracks, oil traces, arcing damage or anything

    - replaced for the 2nd or 3rd time today the fuel pump just to be sure.

    - replaced fuel filter and later made sure the arrows were pointing towards the front of the car...

    Next steps:
    - check the fuel filter again to see (if that's even possible) if it was mounted "backwards" but from a left/right hose perspective

    - replace the plugs with used ones just in case they're faulty (will put new ones in any case once I can find a suitable ref fro my car)

    - take the EM off again to check the cats. Question is: how can they be checked visually? From outside they look super clean, are not corroded or anything...In doubt, I'll just replace them with E39 or E36 catless headers.

    - replace the injectors with the ones you kindly gifted me, Chris.

    If any of you has any idea, please share...
    Last edited by Breeze1; 11-17-2018 at 02:52 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  5. #30
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    Besides the potential for a huge internal intake system leak I mentioned on your other thread, we keep coming back to the fact that although you're throwing all manner of used parts at it, you still haven't done any real diagnostics, sorry.

    You need a fuel pressure test when the symptoms are manifesting, you need to read codes and watch live data for the various sensors, you need a smoke test. And, since you've called the cats into question, you need an exhaust backpressure test. You can't check them visually, well, except maybe with a borescope, and even that's not a valid test.

    Yes, I understand that this stuff isn't available to you, but that doesn't change the fact that it's what you need to diagnose your issue.

    An exhaust leak can be found with a rubber hose, one end in your ear, the other explores around the exhaust. An exhaust leak will also show black soot around the leak spot.

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  6. #31
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    Ok so, although this misfiring issue has taught me not to rejoice too fast, it seems to be gone, for some odd reason. Yesterday when I test drove it "hard" it was with the replacement fuel pump in. After putting mine back I drove slowly home and it's true that there were no hesitations at low revs but I thought it was not significant enough to deduce that the issue was gone.

    Today I couldn't test drive it on open road because of a really bad weather, but at low revs and during a few pulls in 1st and 2nd it behaved well. No more hesitations and the accelerations were back to normal.
    Maybe the replacement pump was bad, maybe the DME needed some driving to adjust to new conditions after fixing the EM slight leaks and putting my separator back in, I don't know.

    Even the "echo" I heard near the EM seems to be gone. It can be heard in the vid I shared below, but only in the vid. In real conditions my ears couldn't hear it.

    I took the cap off with the engine running like you said and it triggers a slightly rough idle , which can barely be heard with earphones, on the vid. You can feel the cap being pulled back on when holding it close to the engine but it's a very light suction effect.

    I hope I'm done with this because there are many more things that need fixing on the car...

    https://youtu.be/LxwVYAJ5nm8

    P.S.: thinking about it, yesterday we found out that the little electric pump located behind the MAF, that helps coolant circulation, would only work when pushing on its connector. We cleaned the connector and its housing with white spirit and it started working by itself again. I don't think it was the culprit unless it was messing up the whole car's electric signal (I did get a "signal ignition resistance" error code on INPA (n°58)).
    Last edited by Breeze1; 11-18-2018 at 02:43 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  7. #32
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    I have been trying to remember every detail of what happened yesterday that could have fixed the misfiring, to know what to do if it comes back and also hoping that my experience could benefit other members.

    And I did remember something that might explain it all lol. Before I swapped my engine I used to constantly hear what sounded like a faint, high pitched echo of the engine's sound coming from somewhere behind the steering wheel, approximately where the brake servo unit is located.

    I had to hear that sound yesterday to realize that it had disappeared after swapping the engine. I don't think that sound should be heard and my servo unit might be faulty, but it reappared the exact same day the misfiring issue *seemed to have gone*, and my mechanic did take off and put back in the hose coming from the vacuum system several times lately. So I have a feeling something was stuck/leaking and got fixed somehow.

    Maybe fixing all the intake leaks had a belated side effect on the servo?
    Last edited by Breeze1; 11-19-2018 at 01:47 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  8. #33
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    Ok so I was right not to rejoice too quickly: after a very short break the issue is back. Tomorrow is a national holiday here so here is what I'm planning to do: spark plugs/fuel filter (make sure it's mounted as it should, since it's new anyway)/ injectors replacement, servo unit check.

    I think fuel pump and intake leak anywhere around the intake manifold can be safely ruled out at this point.

    I would appreciate to have a feedback on the vid I posted above in case there is anything that sounds wrong with the car. Also, can a servo unit leak/malfunction cause misfiring or am I just wasting my time? That sound that was back when the car seemed fixed is gone again. I'm suspecting it is linked to the issue somehow, but I'm no professional so it could be complete BS, I don't know...
    Last edited by Breeze1; 11-20-2018 at 05:10 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  9. #34
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    It was the stupid MAF sensor all along

    Yesterday after replacing injectors, spark plugs (with used BR6EQUP... ones while I order new ones), and checking a bunch of other things to no avail, I replaced it and now the misfiring is gone (fingers crossed).

    I had already tried to replace it but the one I had put in didn't work. AND I had no error codes triggered in INPA (well yes, once, but when I cleaned it and cleared the code in INPA it never came back, which led me to rule it out).

    Now the car seems a bit slow to pick up speed between idle and 1500/2000rpm unless I press the gas pedal more than I used to with the old MAF, but once it goes it doesn't misfire anymore.

    I replaced it with a quality used one since the new ones are of lower quality and I intend on ordering a new one from a good brand.

    328Power04, I remember well that you told me a MAF sensor from a 330i would run poorly unless the DME is tuned accordingly, but how poorly? As in not better than with a stock 328i's, or worse? I was thinking of running a full 330i setup with stock airbox, MAF, and the larger hose behind it and later on tune the software, but if it runs like crap I obviously won't do it.
    Last edited by Breeze1; 11-22-2018 at 03:46 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  10. #35
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    A single hole being bigger will not make any more power, but will certainly cause the computer all kinds of errors in calculations.

    The engine is a SYSTEM. You've really got to stop seeing it as a bunch of parts that you can just swap with incorrect parts, haphazardly.

    When you have an assembly of unmatched parts, you've already got multiple reasons for bad behavior.

    Adding MORE mismatched parts just makes the problem worse, and diagnosis more impossible.

    Quit trying to make it faster before making it run correctly. You do not need more variables. You need to do appropriate testing, and rule out variables.

    Even yesterday, you replaced your old injectors with ones that are perfect, and proven....at the same time as you threw used sparkplugs in it, and then a used MAF. And then you say "misfiring is gone, it was the MAF" .... "fingers crossed". But the "new" MAF makes it slower at low rpms, but once the engine turns higher RPMs, the misfires go away. Therefore, it's not fixed at all, and given the intermittent nature of your misfiring, and the fact that you changed three things, two with highly questionable used items, you haven't narrowed it down, either. What if one of your old injectors was bad, but one of your "new" sparkplugs is bad?

    WHICH cylinders are misfiring? When you swap multiple items, even allowing a few minutes of driving in between, on a car that has known - intermittent --misfire issues, you can't possibly point to the used MAF as being the cure.

    As far as I know, we still have no evidence that your CCV apparatus isn't leaking massively, or that your intake isn't leaking, or that your fuel pressure is right.
    Last edited by bmwdirtracer; 11-22-2018 at 08:53 PM.

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  11. #36
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    Chris, I know that an engine runs as a system. That's the reason why I already have full 330i's exhaust line and intake manifold on it; adding an airbox, MAF and hose from a 330i (on a 2.8l engine) would be just completing the "air loop" (intake/exhaust) and making it more homogeneous rather than messing it up IMHO. So from a strictly hardware standpoint, it would make more sense than my current setup, since the M54B30's IM would be fed air by parts it was originally designed to work with, rather than by restricting ones (current MAF/hose are the ones that come with 2.5/2.8l engines and their more restricting IM's). The question that remains is how would the M52TUB28's software deal with it...

    Regarding the other variables, I obviously tested them separately and did not throw everything at once at the car and claimed the MAF was the culprit... After each installation/testing the misfiring came back, except for the MAF (so far at least). The car feels "slower" at low revs unless I press the gas pedal more than I used to (If I do, it's not any slower than it used to be, maybe even faster or let's call it "jumpier"). It's a bit like at low revs the ratio "gas pedal pressure/acceleration" is less linear than it used to be. I thought it could just be the MAF's behaving a bit differently and like I said before, I intend to replace that MAF (and the spark plugs) anyway. Maybe the car would behave better with new parts, maybe not. The spark plugs I used are in good shape, so is the MAF.

    About the intake leaks, I have stated several times before that they were fixed, as well as exhaust ones, and provided a vid for the members' appreciation (I even asked twice for feedback on it)

    I understand that there is a "don't upgrade it, just fix it and stop messing around" philosophy on this forum, which is fine, but it's just not how I see things. I have a 17 yo car that is bound to having stuff failing relatively often, and I would rather take that as opportunities to upgrade it along the way and make it better. It will make the time and money spent on it more useful and it will make me happier, as I see it evolving along the way rather than throwing money just to keep the poor thing surviving...
    Last edited by Breeze1; 11-23-2018 at 05:52 AM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  12. #37
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    Nayl, I know you think I'm being a stodgy old fart, but neither I nor anyone else here is saying "don't upgrade it". We're saying "Fix it, THEN upgrade it". This, to prevent adding further variables to an already difficult diagnosis.

    As for intake leaks having been cured, the last I heard was that you had a CCV valve / separator which had no diaphragm, and a pipe from the valvecover that was heavily dripping oil.

    Just on this page, in the 3 weeks represented above, you've gone through several cycles of "it's fixed", and "it's not". In the very first post on this page, you begin with, "stuttering is NOT fixed", and then 2 paragraphs later, it is.

    Regarding the fuel pump replacement vs. a pressure test, my point is that no matter how many times you replace the fuel pump, you still aren't sure that you have the correct pressure, unless you test. (What if the return line is kinked?)

    Anyway, I hope, for your sake, that everything is truly fixed now, and that your problems with misfires and poor running are gone, so that you can drive your car with a smile on your face instead of "feeling like you're chasing a ghost and can't enjoy your car anymore".

    All the very best!

    Chris

    Chris Powell
    Racer and Instructor since, well. decades, ok?
    Master Auto Tech, owner of German Motors of Aberdeen
    BMWCCA 274412
    German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471

  13. #38
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    Thanks for your reply and your help Chris. My feedback in blue in your text.

    Quote Originally Posted by bmwdirtracer View Post
    Nayl, I know you think I'm being a stodgy old fart, but neither I nor anyone else here is saying "don't upgrade it". We're saying "Fix it, THEN upgrade it". This, to prevent adding further variables to an already difficult diagnosis.

    I don't think that at all, it's just that I'm trying to do both at the same time. Instead of replacing once to fix the car and later on another time to upgrade it, I'm trying to save time/money by replacing broken parts with upgraded ones whenever it makes sense. In the case of the MAF sensor and matching hose, it seems to be the case as far as hardware goes, since everything else in the "air circuit" (IM, exhaust line) is taken from a 330i. Software is a different thing, which is why I asked 328Power04 to kindly elaborate on what he meant by "working poorly".

    As for intake leaks having been cured, the last I heard was that you had a CCV valve / separator which had no diaphragm, and a pipe from the valvecover that was heavily dripping oil.
    It probably isn't missing that diaphragm since, further to your instructions, I did try taking the oil cap off with the engine running (I made a vid and shared it here so you could assess if it's working properly) and there was no honking or anything unusual. There was no oil dripping pipe as far as I remember. I also took apart the whole IM and checked every big and little hose/gasket, you name it, and even replaced hoses that were not leaking per se, but looked a bit suspicious. So I'm really confident Intake leaks are gone.

    Just on this page, in the 3 weeks represented above, you've gone through several cycles of "it's fixed", and "it's not". In the very first post on this page, you begin with, "stuttering is NOT fixed", and then 2 paragraphs later, it is.

    Regarding the fuel pump replacement vs. a pressure test, my point is that no matter how many times you replace the fuel pump, you still aren't sure that you have the correct pressure, unless you test. (What if the return line is kinked?) I did the "rudimentary" test you mentioned once since I don't have the FPG: unscrew that little "grommet" on the fuel ramp after letting the car sit for 15-20 minutes and push a bit on the little black plastic (for lack of better words) with a thin screwdriver: it squirts fuel hard (about 40cm high).

    Anyway, I hope, for your sake, that everything is truly fixed now, and that your problems with misfires and poor running are gone, so that you can drive your car with a smile on your face instead of "feeling like you're chasing a ghost and can't enjoy your car anymore".

    All the very best!

    Chris
    Last edited by Breeze1; 11-23-2018 at 09:43 AM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  14. #39
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    You seem to have a very hard time trusting us.

    MAFs run on 0-5V signal. 0V = no measured air, 5V = fully saturated.


    When you change MAF size, you change the velocity of the air across the sensor.

    Let's say your engine is pulling 200mg of air per stroke at some point. Your currently calibrated MAF will measure some 200mg/str of air +-, at some 2V of signal (example value). The DME will see the 200mg/str and calculate fuel for that.

    Ok, same conditions, and we slap on a 3.5 inch MAF. You have not increased airflow in any way, so engine is still processing 200mg/str of air. However, the larger tube of the 3.5 inch maf will have less air velocity across the sensor. So the MAF will report much much less now.

    Keep in mind that flow dynamics apply. The change in flow rate is not linear, but rather propotional to the radius to the 4th power.

    So now the MAF sends a value of 1.5V (just an example) instead, and it will fuel for some 150mg/str of air, but you actually have 200mg/str of air. You will be very lean.

    Sure adaptation may cover for some of it... And people will say, "it runs fine".. well yea, it runs because it's using adaptations to add +10-15% fuel. Riding the limit of adaptations. But as soon as you run into a small vacuum leak, or poor fuel, it will be even leaner and cause dangerously lean conditions.

    Also, on full throttle, your car dme does not adjust fueling.. it's open loop. So you will run lean, and no adaptations. Full throttle and lean = dangerous.
    Last edited by 328 Power 04; 11-23-2018 at 12:29 PM.
    -Abel

    - E36 328is ~210-220whp: Lots of Mods.
    - 2000 Z3: Many Mods.
    - 2003 VW Jetta TDI Manual 47-50mpg
    - 1999 S52 Estoril M Coupe
    - 2014 328d Wagon, self-tuned, 270hp/430ft-lbs
    - 2019 M2 Competition, self-tuned, 504whp
    - 2016 Mini Cooper S

  15. #40
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    Thanks Abel. It has nothing to do with trust believe me (I'm in no position to judge what's right or wrong anyway, and if I didn't trust you I wouldn't have flashed my DME with the software ref you provided me with, on a newly installed engine).

    And I'm aware that an M54B30 MAF wouldn't improve anything without proper software tuning.
    It's just a case of "while I'm at it" (replacing the MAF) and if things wouldn't have been made worse than with a stock MAF (adaptations like you said, but apparently they're limited), I would have installed a 3.0 MAF and tuned the software down the line.

    I believe the airflow my engine is getting is significantly higher with my current "CAI" than with a stock 328i airbox judging by the sound the exhaust makes (I know the intake sound is not an indication by itself since the filter is not shielded) but since I have no other way of measuring it than a narrow band A/F gauge, to make sure that I'll not be running lean, I'll just stick with the stock MAF for now.

    P.S.: I do have INPA's (or was it Winkfp's? I can't remember) live data though. I don't know if that would help
    Last edited by Breeze1; 11-23-2018 at 12:57 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  16. #41
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    You have the tools to measure it for yourself. Exhaust noise on the other hand is a very poor indicator.

    Simply log MAF data with Testo. Testo takes the same data from INPA and allows you to log it in a spreadsheet file. That way you pay attention to the road, not to your computer.

    Either look at MAF Volts, or MAF signal in kg/hr.

    The limit for MAF Volts is 5V, and in mg/str the limit for your DME/MAF combo is 778kg/hr.
    If on sustained full throttle you overshoot those values, then your MAF is too small. (But do not base this on crap aftermarket MAFs, as their sensor can be completely miscalibrated for Voltage output. This is why aftermarket $30 MAFs suck)

    It takes very very aggressive cams or forced induction to surpass that.

    Keep in mind, the 2.8L has a cylinder volume of 467cc, which is theoretically 467mg/str of air on a naturally aspirated engine. Intake manifold design contributes a little extra air through resonant pulsations (a huge study to explain why it happens), but you'll never really force extra air to oversaturate your MAF. Very long cam durations from aggressive camshafts help a little more, but this isn't the case here.
    Last edited by 328 Power 04; 11-23-2018 at 02:12 PM. Reason: units
    -Abel

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  17. #42
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    Alright, will do, just for the sake of "science" since apparently I'll still be far from the limit with my setup

    I'm not trying to be a smarta** here, but I wonder why Bmw went with a 3.5" MAF for the 330i, which is NA? I mean the cylinder volume and cam profile must not be that different from the 2.8's?
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  18. #43
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    The M54B30 has a hotter intake cam, in addition to the higher displacement. It makes a difference.


    On your car, even with good mods, you'd be lucky to get up to 650 kg/hr (out of 778 measurable) MAF flow at high rpm.

    The M54B30 would go near 700, if not just over. Enough for BMW to choose a larger maf.
    -Abel

    - E36 328is ~210-220whp: Lots of Mods.
    - 2000 Z3: Many Mods.
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  19. #44
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    Which hints at one of the mods I could end up doing and that WILL require a change of MAF sensor haha.

    But not before I learn how to tune my software for that stuff, since my car is also meant to be a "test bed".

    Thanks for the explanation!
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  20. #45
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    Deja vu,
    very similar to Wadi I fear.
    Does everyone across the pond love to Frankenstein their engines?

  21. #46
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    Quote Originally Posted by MIKYZZ4 View Post
    Deja vu,
    very similar to Wadi I fear.
    Does everyone across the pond love to Frankenstein their engines?
    Well like you might have guessed I wanted to know more about who you're comparing me or my plans to, and while I truly had a good read and a good laugh thinking that you're comparing a patchwork of an engine bought "as is" to a (potential) well documented intake cam upgrade on an otherwise stock engine, made by not the guy who's selling the car but by the one who intends to keep it, I still think you're a bit though on the guy, because as many have noted experiencing stuff comes at a risk and yes, sometimes catastrophic failures, but as long as one is willing to take ownership for it I say just let it be...
    Last edited by Breeze1; 11-23-2018 at 06:33 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
    5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.

  22. #47
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    MauiM3Mania is offline Observer/Master Skeptic Moderator
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    Quote Originally Posted by MIKYZZ4 View Post
    Deja vu,
    very similar to Wadi I fear.
    Does everyone across the pond love to Frankenstein their engines?
    I too felt a Wadi-esque feeling this morning.

    Quote Originally Posted by Breeze1 View Post
    Well like you might have guessed I wanted to know more about who you're comparing me or my plans to, and while I truly had a good read and a good laugh thinking that you're comparing a patchwork of an engine bought "as is" to a (potential) well documented intake cam upgrade on an otherwise stock engine, made by not the guy who's selling the car but by the one who intends to keep it, I still think you're a bit though on the guy, because as many have noted experiencing stuff comes at a risk and yes, sometimes catastrophic failures, but as long as one is willing to take ownership for it I say just let it be...
    The common theme may be that some people ask for input and ignore the suggestions provided by professionals.
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  23. #48
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    Let me just state that I have nothing against performance mods,
    after a well thought out and researched approach to any engine specifications changes.

    Slapping replacement parts on an engine, solely based on an assumption it might perform better,
    is not an informed or smart way of enhancing engine performance.

    Funny that you would not assume that the engineers over at BMW have already thought about squeezing out more power with simple component changes. Their engine design and development teams are pretty knowledgeable.

  24. #49
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    We're not gonna run a debate over this (at least I'm not taking part in it). The post is here for anyone to look at and draw his own conclusions. I know where I stand.

    Mikyzz4: if it were only up to the engineers what products are marketed with what characteristics embedded in them, we would probably be driving flying cars by now. It's just that innovations are introduced at a relatively incremental speed to leave room for market leverage and profit, as well as to adapt to new regulations. It's not in the manufacturers' best interest to put state of the art technology in their cars when not necessary.
    In this case the transition from 328i to 330i was probably ready at the very time the 328i was put on the market.
    Last edited by Breeze1; 11-23-2018 at 07:44 PM.
    "If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
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  25. #50
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    Cool Breezy,
    Peace;out!

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