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A turbo encabulator (youtube it) makes more sense to me at this point than whatever you're talking about, but I have a verified good MAF in a box I can ship to you free if you want it. Let me know.
A turbo encabulator (youtube it) makes more sense to me at this point than whatever you're talking about, but I have a verified good MAF in a box I can ship to you free if you want it. Let me know.
Lmao. Im sure it probably seems easier to understand how to build an Infinite Improbability Drive from scratch than to make sense of all this tuning crap, but I promise it is all pretty straight forward once you get your arms around what all the different terms mean and how they interact with each other. I definitely plan to spell it all out when I make the How-To thread (after I finish my own damn problems, mind you) so 'tards like you & I can make sense of everything. As for the MAF, sure, Ill take it so at least I can do some testing and see how it compares to mine. Ill shoot you a PM.
Im looking through various datalogs of mine and Im seeing the same pattern - a massive increase in MAF voltage fluctuation around 4k RPMs. Im seeing one where the fluctuations there are an entire volt - pretty much inconcievable to me that a healthy MAF would have this behavior, but idk, you guys tell me lol.
Paid $101 a year ago so it's still pretty close. Great MAF.
I would just call AutoZone and verify the part #, make sure it's MAF0095
But I think you're on to something as the 2014 FSM EC section 191 [MAF] Component Check section under "without Consult" states to watch for linear voltage rise between 2500 and 4k rpm when testing the MAF. Testing the MAF without Consult is pretty limited in the FSM.
I'm not surprised to see the noise on the MAF voltage. The ECU obviously filters most of that out as your IPW won't change that drastically. I'll see if I have an old datalog with MAF voltage... Found one Noisy MAF
Last edited by freezer; 04-11-2020 at 02:52 PM.
Reason: Added MAF log
I'm not surprised to see the noise on the MAF voltage. The ECU obviously filters most of that out as your IPW won't change that drastically. I'll see if I have an old datalog with MAF voltage...
Believe me, Ive read that thread enough times to the point I could probably recite it from memory lol.
Im honestly just swinging away blindfolded right now, praying to connect with the piñata. All i know for certain is I get dangerously lean at 4k. I just happened to notice that my MAF voltage signal seems to have a lot of fluctuation, and figured maybe that might be the cause of my troubles since I cannot for the love of god figure out another cause. The amount of “noise” drastically increases at the exact point that I am getting the AFR spike around 4k RPM. Its hard to say though, I dont really have a “normal” baseline to compare against. Oscillations in the signal voltage are practically immeasurable at idle, go to between 0.3-0.6v in range during cruise, and at around 4k RPM, the range becomes an entire volt in width. Its also worth noting that if I “skip” the 4k RPM range by shifting down in gears, that this problem doesnt occur. Its only in the 4k range, and it happens in every single one of my logs, including before I started reflashing and was using an Apexi NEO.
In my mind its either this MAF signal noise that is causing the issue, or its another symptom of whats causing my issues.
Would you happen to have a scale of the noise (y-axis displaying voltage)?I think noise is normal, what Im concerned about is the intensity of the noise. Like whats the voltage at one of those peaks vs one of the neighboring lows?
All i could dig up on google was that noise thats 0.1 or 0.2v in ‘intensity” is normal, but more than that is not. Thats based off some random stranger from some random forum so idk if thats accurate at all.
I'd be interested to see the log file of a WOT pull. RPM, IPW, MAF voltage, and Load.
So apparently I dont have IPW set as a parameter in any of my logs, Im assuming this is Injector Bank 1/2? Going to go do a run right now. In the mean time heres a log, doesnt have the pulsewidth though.
Would you happen to have a scale of the noise (y-axis displaying voltage)?I think noise is normal, what Im concerned about is the intensity of the noise. Like whats the voltage at one of those peaks vs one of the neighboring lows?
All i could dig up on google was that noise thats 0.1 or 0.2v in ‘intensity” is normal, but more than that is not. Thats based off some random stranger from some random forum so idk if thats accurate at all.
There's scaling on the LHS of the charts. It's worse on the 5.5 gen MAF, but doesn't look like much more than 0.3V 6th gen MAF 5.5 gen MAF
I also attached the ROM being used, should be downloadable at the bottom of this post.
Edit: Freezer, my apologies but im still not seeing any Y-axis scale in the two pics you uploaded. I can see what the different colors are, but I dont see any reference to the Y-axis as to what values are being displayed.
Originally Posted by slvr2KSE5
Possibility this is intake resonance related to the 4"?
Maybe, idk. Its one of Douglas Sands'/CGR's, hes been cranking them out for the better part of this last decade. Plenty of people seem to use it without any such issues so I dont think this is the cause.
That MAF voltage is messed up. I'd reason it's possibly due to a couple of things:
VIAS interference. The factory puts these things on for a reason, there's additional cost to produce them so you know it's not just for kicks, and in this case it's not emissions! The 2nd gen DE (Maxima intake) has separate settings for each solenoid. Notably, the RPM range for solenoid 'A' is 1400 to 5000 RPM, while the other (smaller) one is 1800 to 3800 RPM. You can't run these independently, but you could try changing the upper limit to 5000 and see if that moves the problem, or potentially eliminates it. Easy thing to check!
The intake diameter is too large. (you're not using the full range of the MAF, I saw in your other log the max voltage was about 3.6V) This still shouldn't produce the results you're seeing, but in my opinion it's not helping.
Or your MAF just sucks...
Megalog viewer shows the "MAX" and "MIN" of each scale on the LHS of the plot, color coded.
Nothing against CGR intakes, but volume of sales doesn't mean much. Most people don't bother to install a wideband, just butt dyno! That and the 2nd gen DE engine performs differently than the old DE, and only in the last 3 years have people been tuning these ECUs properly and not piggyback.
Thanks guys. Im thinking its a combination of pretty much all these factors - crappy MAF, VIAS interference, intake resonance issues.. Going to get a new MAF and test the VIAS theory in the meantime.
Im also going to look more into how the 7th gen VIAS operates. I think I have a potential work around for those of us running the swap so that we can make the most of it. Stay tuned!
Im also going to look more into how the 7th gen VIAS operates. I think I have a potential work around for those of us running the swap so that we can make the most of it. Stay tuned!
Let me know later in the week at some point if you find anything beyond RPM points for the solenoid. For that we can just look in the FSM. Im curious if anyone published any information that goes over ideal RPM points for a car thats tuned - only a dyno day could divulge those figures.
Originally Posted by Child_uv_KoRn
Zip time them open, block em off or leave it as is. Problem solved XD. From what I remember, they don't do much of anything on a tuned car.
I imagine youre correct to a degree. I cant see it affecting peak HP, but I dont see how tuning would eliminate the low end torque gains. Regardless of tuning, the VIAS is able to change the velocity of air entering the motor. I could just disable it and tune accordingly but having a physical change in intake runner size isnt something tuning can replicate I dont think. In any case, I think I should be able to get the VIAS to operate the same way the 7th gen has it - it should actually be quite easy. The challenging part is going to be figuring out where to set the VIAS points for maximum power, since the stock points are not going to be as effective on a tuned motor. For that I would need to rent a dyno, which as of right now isnt quite on my radar yet. But yeah for now, Im gonna determine if thats whats causing the AFR spike, and probably just disable the solenoid until im able to get 100% VIAS function the way Nissan intended for that manifold rather than the ghetto crap I have going on.
Originally Posted by User1
If you don't put another MAF in it and figure this out, I don't even care about pictures. You're dead to me.
Lol patience my dude, theres nobody on Earth that wants my car tuned more than I do. I have a new Hitachi MAF coming in the mail later this week, so ill pretty much be laying low until Im able to swap that in. But yeah, this isnt a project im going to hang up unfinished, Im grinding this crap out until the very end lol. Its literally the last thing I can do to my car to get more power, I already have every other upgrade or bolt-on. Looking forward to it, because then I can start tidying up all the cosmetic stuff on my car. I feel I should have a car thats actually badass before I make it look badass.
I imagine youre correct to a degree. I cant see it affecting peak HP, but I dont see how tuning would eliminate the low end torque gains. Regardless of tuning, the VIAS is able to change the velocity of air entering the motor. I could just disable it and tune accordingly but having a physical change in intake runner size isnt something tuning can replicate I dont think. In any case, I think I should be able to get the VIAS to operate the same way the 7th gen has it - it should actually be quite easy. The challenging part is going to be figuring out where to set the VIAS points for maximum power, since the stock points are not going to be as effective on a tuned motor. For that I would need to rent a dyno, which as of right now isnt quite on my radar yet.
If the change is outside of margin of error, then virtual dyno is plenty capable.
after I installed 3.5" intake MAF voltage when idling changed from 1V to 0.8V, is this normal guys ? (sorry for off-topic)
What are you doing for tuning? Did you rescale your MAF table to account for the larger MAF tube?
Youre getting less voltage because everything is exactly the same except for the intake size. The same amount of air gets pulled into the motor, but since the diameter of the tube is wider, the air is less dense, and therefore the sensor has less air passing it then it did previously with the stock MAF tube. Since the sensor sees less air, the ECU determines that less fuel is needed to match that air. This, however, is wrong - you only changed the size of the intake and what the sensor is measuring, NOT the actual amount of air entering the motor.
The result is the same exact amount of air entering your motor now produces a lower voltage on the MAF sensor, tricking the ECU into providing less fuel, and your motor ends up running lean. Lower idle voltage is “normal” if you didnt properly tune your car - its not normal if you did tune properly.
What are you doing for tuning? Did you rescale your MAF table to account for the larger MAF tube?
Youre getting less voltage because everything is exactly the same except for the intake size. The same amount of air gets pulled into the motor, but since the diameter of the tube is wider, the air is less dense, and therefore the sensor has less air passing it then it did previously with the stock MAF tube. Since the sensor sees less air, the ECU determines that less fuel is needed to match that air. This, however, is wrong - you only changed the size of the intake and what the sensor is measuring, NOT the actual amount of air entering the motor.
The result is the same exact amount of air entering your motor now produces a lower voltage on the MAF sensor, tricking the ECU into providing less fuel, and your motor ends up running lean. Lower idle voltage is “normal” if you didnt properly tune your car - its not normal if you did tune properly.
Thank you for response, so I just took old K Value and multiplied it to 88/71 (new size divided to old size), I am too lean but it's drivable. please explain what is the proper way to rescale things? MAF Tuning or just multipliers such MAF Factor, K Multiplier & etc.
Thank you for response, so I just took old K Value and multiplied it to 88/71 (new size divided to old size), I am too lean but it's drivable. please explain what is the proper way to rescale things? MAF Tuning or just multipliers such MAF Factor, K Multiplier & etc.
1.05 would be +5%, etc. Drive around and try to hit all over the fuel map for a long time.
After you get it really close, then calculate for fuel table. That should be so close that you won't need much manual adjustment.
Last edited by Child_uv_KoRn; 04-14-2020 at 02:25 PM.
1.05 would be +5%, etc. Drive around and try to hit all over the fuel map for a long time.
After you get it really close, then calculate for fuel table. That should be so close that you won't need much manual adjustment.
I am using NDS2 for logging, honestly I can convert WB Sensor voltage to AFR values, if I change all the headers and add NDS2 log data to this tool, it will do the job ?
Thank you for response, so I just took old K Value and multiplied it to 88/71 (new size divided to old size), I am too lean but it's drivable. please explain what is the proper way to rescale things? MAF Tuning or just multipliers such MAF Factor, K Multiplier & etc.
If you only changed the MAF tube diameter, just rescale the MAF multiplier (aka MAF factor) by the same proportion of change. You could alternatively adjust K (fuel multiplier), it the same math, just moving the numbers around in the equation. You just pick one though, not both.
Your problem is probably because youre applying the numbers wrong. You have to use the change in area, not the change in diameter - the proportion in change in diameters isnt that much, but the change in area is quite significant. Just look up the formula for finding the area of the circle, do that for both old & new intakes, and use that proportion of change for your MAF scaling.
I am using NDS2 for logging, honestly I can convert WB Sensor voltage to AFR values, if I change all the headers and add NDS2 log data to this tool, it will do the job ?
Yeah. You only need MAF, corrections and the stock O2s. Forgot that NDS2 doesn't log BFS (so obviously can't calculate fuel table). But it'll work for MAF.
Time - A/F CORR-B1 (%) - A/F CORR-B2 (%) - MAS A/F -B1 (V) - NB-O2 SEN 1-B1 (V) - NB-O2 SEN 1-B1 (V)
Is your idle at 0 correction? Adjust K till it is, then log and calculate maf table. Don't forget to zero out fuel table.
Last edited by Child_uv_KoRn; 04-14-2020 at 07:09 PM.
If you only changed the MAF tube diameter, just rescale the MAF multiplier (aka MAF factor) by the same proportion of change. You could alternatively adjust K (fuel multiplier), it the same math, just moving the numbers around in the equation. You just pick one though, not both.
Your problem is probably because youre applying the numbers wrong. You have to use the change in area, not the change in diameter - the proportion in change in diameters isnt that much, but the change in area is quite significant. Just look up the formula for finding the area of the circle, do that for both old & new intakes, and use that proportion of change for your MAF scaling.
can you provide more info please? you mean pi*r2?
Originally Posted by Child_uv_KoRn
Yeah. You only need MAF, corrections and the stock O2s. Forgot that NDS2 doesn't log BFS (so obviously can't calculate fuel table). But it'll work for MAF.
Time - A/F CORR-B1 (%) - A/F CORR-B2 (%) - MAS A/F -B1 (V) - NB-O2 SEN 1-B1 (V) - NB-O2 SEN 1-B1 (V)
Is your idle at 0 correction? Adjust K till it is, then log and calculate maf table. Don't forget to zero out fuel table.
idle is 125 sometimes, that explains I didn’t calculated K right?
idle is 125 sometimes, that explains I didn’t calculated K right?
Yeah, that's why it's so lean. It's adding as much fuel as it can. Add 25% to K, see where it's at. Then add/subtract to K again depending on what corrections says. You'll be dead on and can tune maf table (it should be fully driveable but maybe rich).
Last edited by Child_uv_KoRn; 04-15-2020 at 01:16 AM.
Yeah, that's why it's so lean. It's adding as much fuel as it can. Add 25% to K, see where it's at. Then add/subtract to K again depending on what corrections says. You'll be dead on and can tune maf table (it should be fully driveable but maybe rich).
I did what you said, MAF g/s not going over 120 and on stock setup on idle 650 rpm gm/s was 2.9 now it's 1.5. I am thinking it's not normal
So, bad news. Still cannot figure out this AFR spike problem. Replaced the MAF with a brand new Hitachi sensor, which didnt really change anything - either this sensor is bad right out the box, or more likely, its not the real issue. I disconnected the VIAS solenoid to see if that was causing the spike - no change. I even unwired the Apexi NEO unit just in case it was somehow interfering with the signal.
Going to test with the stock intake system and see what happens with that, going to wait til tomorrow since its getting dark and cold and windy now. Idk though guys, Im stumped.
Edit: on a side note, if it does turn out to be an issue with the intake itself (ie; resonance) that isnt exactly the worst thing - as long as it is predictable and repeatable, it can simply be tuned out of the equation. Just would need to 100% confirm that is the cause so I dont get hit with any unhappy surprises.
Gross. What have you got on for headers? If it is the intake I'd rather swap it out than tune around it. That's a mean issue you're dealing with.
Yeah, tell me about it. Im finding it incredibly hard to believe that all these people have 4” intakes and nobody knows of this problem.. then again, the only people who know how to tune typically dont broadcast their work either. I honestly am pretty much sold on a Nisformance 3.5” intake setup, especially since they use the slot MAF sensor. But i cant walk away from this unfinished, itll drive me mad until the end of my days lol. Not to mention that I still have not proved it is indeed the intake causing this, although I literally cannot fathom what else could possibly be causing it at this point. I really thought it was gonna be the VIAS or the sensor but it aint.
As far as headers, you mean like exhaust? Im running cattmans, which have been going faithfully strong since I first got them two maximas ago. Probably the one single part on the entire car that gets me geeked every single time I look at it. One day Ill have to do them justice and get them polished and maybe ceramic coated because right now they are looking their age lol.
We have very similar setups. I've also got Cattmans (only 2 years old!). The main differences are I've got an Injen intake for a 6th gen (slot style) a side branch resonator on my y-pipe (no idea what effect it is having, it's primarily intended to eliminate drone) and am running dual VIAS.
Paid $101 a year ago so it's still pretty close. Great MAF.
I would just call AutoZone and verify the part #, make sure it's MAF0095
But I think you're on to something as the 2014 FSM EC section 191 [MAF] Component Check section under "without Consult" states to watch for linear voltage rise between 2500 and 4k rpm when testing the MAF. Testing the MAF without Consult is pretty limited in the FSM.
Let me know.
Hi 0095 is the wrong maf for our car. Its a pathfinder maf. This is why it runs lean at those ranges. I experienced this too as it was labeled as the correct maf on ebay but is incorrect. 0099 Is the correct maf. Here is the quote I got from a Hitachi tech about why fueling was dropping out unexpectedly.
"I don’t see a part number on the receipt but it looks like they sold you the incorrect sensor if it is MAF0095. The part number on the sensor should be either a MAF0099 (from 12/2001) or MAF0094 (to 12/2001). The MAF0095 only fits on the Pathfinder which tells me there is a physical and/or tuning difference between the two 3.5L engines for the two different applications. That is most likely why you are having issues with the sensor not reading correctly in the higher RPM range."
Not sure if this is your lean prob but hope this helps you not get the wrong maf.
Hi 0095 is the wrong maf for our car. Its a pathfinder maf. This is why it runs lean at those ranges. I experienced this too as it was labeled as the correct maf on ebay but is incorrect. 0099 Is the correct maf. Here is the quote I got from a Hitachi tech about why fueling was dropping out unexpectedly.
"I don’t see a part number on the receipt but it looks like they sold you the incorrect sensor if it is MAF0095. The part number on the sensor should be either a MAF0099 (from 12/2001) or MAF0094 (to 12/2001). The MAF0095 only fits on the Pathfinder which tells me there is a physical and/or tuning difference between the two 3.5L engines for the two different applications. That is most likely why you are having issues with the sensor not reading correctly in the higher RPM range."
Not sure if this is your lean prob but hope this helps you not get the wrong maf.
Thx
Hey dude, you have no possible idea how much help you just gave me, thank you. This pretty much explains the root of all my problems with this car...
New intake and MAF on the way. Nothing wrong with this intake, it turns out, but new Hitachi MAF0099 is ~250 bucks and new slot style MAFs are under $60 and superior in every regard, so thats the way I am going. I suppose if I found out the voltage table for a pathfinder I could make this sensor work just fine, but at this point, Im over it.
User1, I would strongly recommend you stop using that sensor, or at least stay away from WOT. Pretty sure my “”original”” sensor was replaced with one of these by a previous owner, since both old and new sensors I have right now are doing the same thing. And it probably explains why my original motor ended up blowing, since I never figured out what led to it losing compression... ouch.
I guess I at least have closure now, right? LOL
edit: contacted amazon, they will be pulling that item until the description is accurately updated
Hey dude, you have no possible idea how much help you just gave me, thank you. This pretty much explains the root of all my problems with this car...
New intake and MAF on the way. Nothing wrong with this intake, it turns out, but new Hitachi MAF0099 is ~250 bucks and new slot style MAFs are under $60 and superior in every regard, so thats the way I am going. I suppose if I found out the voltage table for a pathfinder I could make this sensor work just fine, but at this point, Im over it.
User1, I would strongly recommend you stop using that sensor, or at least stay away from WOT. Pretty sure my “”original”” sensor was replaced with one of these by a previous owner, since both old and new sensors I have right now are doing the same thing. And it probably explains why my original motor ended up blowing, since I never figured out what led to it losing compression... ouch.
I guess I at least have closure now, right? LOL
edit: contacted amazon, they will be pulling that item until the description is accurately updated
Glad to help friend. Hope you can continue your RR tuning adventure. I had bought the 0095 thinking my original oem maf was causing idle issues and maybe it still is. Coupled with the 303 rom though it makes my max scream. Hope to see the same results for you. I'm using straight 3" intake with a cone filter and the PCV's vented to atmosphere. Hmm Maybe the pcv's are causing my idle issue. Might try to plug them back into the intake and see if it helps.
Anything else that you think I can help with please lmk.
Last edited by timbarry; 04-20-2020 at 12:47 PM.
Reason: add info
04-10-2020, 05:35 PM
) I logged A/F Alpha B1,B2
