At wits' end ( short trip )

[Some Fool]

Working on an LS swap ( junk yard 6.0L LQ4 with 317 heads ) with 4L80e ( unknown history ) with 0411 computer (OS 12212156). It starts well but goes lean (15.5-16.5 AFR ) as it warms up and stays that way when driving ( afraid to drive it too far ). We are running a MAF. I must be adjusting in the wrong table or something because adjustments to the "open loop VE" table don't seem to help? What am I doing wrong?
Any help is greatly appreciated.

Attached what I am working with if someone that knows what they are looking at could look it over...

Thank you in advance,
Some Fool

[ralmo94]

If you are running a maf, VE won't make much difference until it goes to blended mode, example acceleration. Steady state operation is controlled mainly by the MAF. To tune the ve, you need to fail the MAF tune the VE, then turn the MAF back on and tune the MAF

[In-Tech]

If you are running a maf, VE won't make much difference until it goes to blended mode, example acceleration. Steady state operation is controlled mainly by the MAF. To tune the ve, you need to fail the MAF tune the VE, then turn the MAF back on and tune the MAF

YES, ^^^^^^this.
The most common mistakes are the pcv lines, pay CLOSE attention to how GM did it and adjust accordingly. Do NOT try to tune around it, especially in the MAF tables. Leave them alone and fix what is causing them to be wrong. Also, it is very common to have a bad MAF sensor reading low. In neutral it should favor around ~6 grams at 600 rpm and ~25 qms 2500 rpm on stock 6l engine. Most stock 6l engines will pull ~230 gms at ~6000 rpm. If you are a lot lower suspect the MAF sensor. Don't buy anything but a real Delphi sensor. I don't even trust AcDelco anymore since most crap is from China.

A recent example was I diagnosed a failing MAF sensor so the guy went down the street to NAPA and bought a 'refurb" MAF and it was worse than the one he had. Sent him back for a Delphi and problem solved except for the needed tune, and btw, stay out of the MAF table unless you think you are smarter that GM that spent who knows how many thousands of man hours making that table correct. If you have a tube screwing with your MAF table, throw it away ;)

[Fast355]

YES, ^^^^^^this.
The most common mistakes are the pcv lines, pay CLOSE attention to how GM did it and adjust accordingly. Do NOT try to tune around it, especially in the MAF tables. Leave them alone and fix what is causing them to be wrong. Also, it is very common to have a bad MAF sensor reading low. In neutral it should favor around ~6 grams at 600 rpm and ~25 qms 2500 rpm on stock 6l engine. Most stock 6l engines will pull ~230 gms at ~6000 rpm. If you are a lot lower suspect the MAF sensor. Don't buy anything but a real Delphi sensor. I don't even trust AcDelco anymore since most crap is from China.

A recent example was I diagnosed a failing MAF sensor so the guy went down the street to NAPA and bought a 'refurb" MAF and it was worse than the one he had. Sent him back for a Delphi and problem solved except for the needed tune, and btw, stay out of the MAF table unless you think you are smarter that GM that spent who knows how many thousands of man hours making that table correct. If you have a tube screwing with your MAF table, throw it away ;)

Unless the MAF is in a stock intake system on a bone stock engine with nearly no overlap it can be 20%+ off in calibration.

[In-Tech]

Sorry Fast, wrong!!!! If it's a cartridge MAF in a weird tube, correct. The truck MAF (Delphi AF10043) doesn't care unless it is too close to the throttle body(common mistake too).

[ralmo94]

It was always my understanding that MAF calibration was done on a test bench without the stock intake tube connected, or air filter. With tight radiuses and bends and what not, these could play with the speed of the air moving across different parts of the MAF.
It was also my understanding that some elements of the tune were left close enough and not dialed in to save time and money as the O2 sensors were required for fine tuning fuel trims anyway. If the MAF is always correct, why do we get fuel trims on bone stock vehicles with no mods, and no defective issues. If a swap was done and the stock intake tube was not able to be utilized I could see the MAF curve being off a little bit. Also it was my understanding that MAF's don't like big cams from the reversion due to overlap,as this causes a pressure wave.
I don't know. But I would definitely make sure everything is connected correctly before attempting to tune MAF curve, but I would also compare closed loop fuel trims to wide band and see if they agree.

[In-Tech]

Obviously GM doesn't tune EVERY vehicle, everything within "tolerance". example, We took a bone stock Camaro off the showroom floor to CARB so we could baseline our testing. Guess what? ...it failed bone stock. Got another one from the dealer, it passed...then we could do our aftermarket stuff and re-test for certification.
You are correct on big cams and reversion double hitting the MAF, this is why distance can be massive criteria, tube size matters for transport delay when tube is larger than the MAF, tuning the MAF table doesn't FIX this but it seems some people get in there and think they are fixing something, you might fix something in one instance and totally fubar it in another instance. Air temp is critical as well as barometer. Also why GM has an air temp sensor in the MAF and even have some MAP sensors with built in air temp.

Just food for thought :)

[Some Fool]

First off, thank all of you all so much.

Ralmo94 I appreciate the clarification as I was unaware of how it works... Obvious new-b question..How do I "fail the MAF"? It is a swap and has the stock cam to the best of my knowledge.

In-Tech I am attaching a few pictures of how I ran the pcv lines and would appreciate guidance if anything looks like it was not routed correctly. The log indicates that the MAF is at 7.23g/s for 620 rpm ( close enough?) but didn't check any other speeds ( I am at about 5K ft above sea level if that matters) but both LTFT is 7.81?

Fast355 I am also including a picture of how I ran the intake tube to get a better idea of what I am working with.

[ralmo94]

First off, thank all of you all so much.

Ralmo94 I appreciate the clarification as I was unaware of how it works... Obvious new-b question..How do I "fail the MAF"?

You edit the dtc code for MAF sensor range. There are two codes either one will work. Basically there is a high and a low frequency. When too high or too low the MAF is determined faulty and it will revert to speed density and use the ve table. You need to change the code for 1st fault sets the ses light, and change the frequency to number that will automatically fail the MAF for example set the high range at like 2hrz. As soon as it reads over 2hrz it should trip the code and go to speed density, you can now tune your VE table

Obviously if you need to fix something with your pcv or something you want to do that first, as ve table is sensitive to any air flow changes.

[Fast355]

Sorry Fast, wrong!!!! If it's a cartridge MAF in a weird tube, correct. The truck MAF (Delphi AF10043) doesn't care unless it is too close to the throttle body(common mistake too).

I am NOT wrong! I have personally witnessed that style MAF as well as the earlier LT1/Vortec/LS1 MAFs do the same thing. The one in particular, I swapped the stock intake tube and box back on to and proved the MAFs (tried 2 different ones) were just fine. I then stuck an 04 LS1 Vette MAF curve in it and it worked with only slight adjustments needed. 5.3L with a 10" long straight 3.75" coupler off the throttle body into a cone filter on a vehicle with very limited engine compartment space. GM uses that same MAF with numerous different airflow tables.

If what you said is correct, this would not happen. The only thing wrong here even was a missing air cleaner element. Fuel trims went +20% the moment the stock air box was mistakingly installed without a filter. Fuel trims were a little off with the open sensor end as well(probably from the mechanical fan blowing air across the sensor) Filter in place and they were sitting near perfect.
https://youtu.be/m-qJ58scPJE

My 4" cartidge MAF has a slightly modified GM Performance Crate 525 HP LS3 MAF curve but I need to add a flow straightner to it.

[Some Fool]

Update: I have pretty much soaked this thing in carb cleaner and have yet to find a leak, so right or wrong, I am moving forward with attempting to tune her. I have watched a few videos but everything seems to be centered around HPTune.. Is there a "how to" for gen 3 tuning?

[Some Fool]

Latest: Managed to fail the VE and get it running fairly well on “MAF only”, but still must be missing something because the short and long fuel trims still pull fuel out..? What am I missing here?

[ralmo94]

Latest: Managed to fail the VE and get it running fairly well on “MAF only”, but still must be missing something because the short and long fuel trims still pull fuel out..? What am I missing here?

You failed the VE and are running MAF only? If so, what did you change to do it?

Or did you mean to say you failed the MAF, so it will use the VE only?

[Some Fool]

Obviously I am lost in trying to do this. I tried to follow Goat Rope Garage vid. "GM Gen 3 MAF tuning Intro, The basics For Mass Air Flow", but he is using HP tune and I am using TunerPro RT so some stuff did not match exactly. As I understand it, this sets it up for "MAF only".
Right or wrong, this is what I did....
Threshold for Airflow calculation to 200
PE MAP Threshold to 0
Deselected Long Term Fuel Trim Correction
Closed Loop Temp Enable to 283
Added %15 to PE Modifier Based on RPM
Deselected Catalytic Converter Protection Enable ( I do not have Cats )
DFCO Enable Temp. set to 280
DFCO RPM all set to 12000
Deselect Use o2 with open Loop Commanded Fuel Table

AFRs looked ok ( around 13 to 15 ), but not steady and could not keep up with quick throttle changes..

[ralmo94]

It's a lot easier to dial the VE in, then turn MAF back on any further corrections apply to MAF if you dialed VE in real close.
You can also just drive so as to try and keep the engine in near steady state condition for MAF.
Disabling Decel, isn't a bad idea if you can't filter your loggs. If you can, you can just filter for throttle position above 1.

[Some Fool]

I will turn everything back on and try to run it.
I do have a wideband (AEM 30-0300 ), but have not been able to get it to log through TunerPro ( Blue pin 68 high and 28 low ).
What I cant understand is that the more fuel I give it, the more (STFT and LTFT ) it just takes out? For all practical purposes this ( except for home made intake tube and headers) is a "stock swap".. why am I so far off?

[ralmo94]

To log WBo2, you should connect the 0-5vlt analog signal to blue pin 55. This is egr position sensor .
You need to have commanded egr to 0, disable egr codes, and zero out egr fuel reduction and egr spark tables.
If you are keeping fuel trims on, all you can do is aim for 0 trim. If you go open loop, you can tune to 14.7 on your gauge, then turn cl back on and tune O2 swing points to match almost no trim.
If you add 10%, and the fuel trims take out 10%, then you add another 10%, fuel trims will now want to take out 20%, the further you get from true, the longer it takes for it to learn what's right.

[Pulse_GTO]

I adjusted your open loop fuel table to be commanding stoich, it was commanding a richer fuel mixture the way it was. I also set your stoich afr to 14.08 to reflect 10% ethanol in pump gas.

There are 2 files attached, one is set up for MAF only, the VE table will be ignored, the second file is SD only, so it will fail and ignore the MAF and run purely on the VE table. Feel free to give these a try and see if you can control your fueling a little easier.

[Some Fool]

EXCELLENT! That is the kind of help that I am looking for and appreciate this very much. I will try to wire the wide band next weekend as described but we threw in the "SD only" bin and made a few adjustments to the VE table just based on watching the displays and have made more progress today than any other day this year. Thank you so much.

[Fast355]

I decided to prove a point with the whole intake tract altering the MAF calibration. This has a LS3 cartridge MAF in a 100mm tube with a Saxon PC 6:1 flow straightner in it. My van reacted the same way the stock van with the GM LT1/Vortec 3.5" MAF in the prior video did with a missing air filter. My MAF calibration started as a GM LS3 525 hp calibration and only needed slight changes to run correctly. From memory had to add about 12% down at 1500hz and remove 4% over 7,000 hz but otherwise it was extremely close. Remove the filter and it nearly stalls.

Excuse the mess outside, just pulled down an old above ground pool and working on a kitchen remodel and I have not had the time to load up a trailer to take to the dump yet. I have seen LS trucks do the same thing with cheap Spectre or Ebay warm air intakes that have a cone filter on the end even with the stock 85mm MAFs. Change the intake tract and you will be tuning the MAF transfer calibration.

https://youtu.be/OtgLUNThifc

[ralmo94]

Change the intake tract and you will be tuning the MAF transfer calibration.

thank you for confirming what I always believed.
True or not I also believed that exhaust modification also alters it, air in air out.
Although maybe not enough to worry about?

[Fast355]

thank you for confirming what I always believed.
True or not I also believed that exhaust modification also alters it, air in air out.
Although maybe not enough to worry about?

Headers definately throw the calibration off. If you took a stock engine and put headers on it, the PCM will read at a higher dymanic airflow and put it in an area of the timing map that GM tuned with very little advance.

[In-Tech]

Fast, I know you're a smart guy, obviously you came to realize this is smart http://www.saxonpc.com/100mm-cells-for-100.html
I end up using multiple honeycombs in intake tracts to calm the tumbling that can occur. When you alter a known good transfer function you will find it isn't accurate at different temps, barometric pressures, altitudes, humidity, etc.

Big camshafts and bad exhaust sometimes require the distance to the MAF to be changed to further away and if packaging doesn't allow this, time to switch to speed density. Sometimes a switch to e78 or e92 computers that allow dual MAF's is an option too.

[Fast355]

Fast, I know you're a smart guy, obviously you came to realize this is smart http://www.saxonpc.com/100mm-cells-for-100.html
I end up using multiple honeycombs in intake tracts to calm the tumbling that can occur. When you alter a known good transfer function you will find it isn't accurate at different temps, barometric pressures, altitudes, humidity, etc.

Big camshafts and bad exhaust sometimes require the distance to the MAF to be changed to further away and if packaging doesn't allow this, time to switch to speed density. Sometimes a switch to e78 or e92 computers that allow dual MAF's is an option too.

I have not run across issues altering MAF transfer functions in nearly 20 years of tuning. Not saying it cannot happen, but it is not something I have seen in many different platforms. I mainly tune GM and Nissan.

I would not go to speed density, it is near pointless and not nearly as accurate. A recalibrated MAF transfer is far more accurate then the best speed density. I had two Dodges that never could achieve accurate fueling, atleast not like a GM or Nissan.

I also converted my TBI to an 85mm MAF years ago.

[Some Fool]

To log WBo2, you should connect the 0-5vlt analog signal to blue pin 55. This is egr position sensor .
You need to have commanded egr to 0, disable egr codes, and zero out egr fuel reduction and egr spark tables.
If you are keeping fuel trims on, all you can do is aim for 0 trim. If you go open loop, you can tune to 14.7 on your gauge, then turn cl back on and tune O2 swing points to match almost no trim.
If you add 10%, and the fuel trims take out 10%, then you add another 10%, fuel trims will now want to take out 20%, the further you get from true, the longer it takes for it to learn what's right.

Ralmo94
I am in the process of getting this all hooked up and adjusting the settings ( after work and should make more progress this weekend ), but the definitions file (.adx ) that I have does not have the egr listed. Would you or someone in this forum happen to have the one I need please?
Thank you in advance.

[ralmo94]

Ralmo94
I am in the process of getting this all hooked up and adjusting the settings ( after work and should make more progress this weekend ), but the definitions file (.adx ) that I have does not have the egr listed. Would you or someone in this forum happen to have the one I need please?
Thank you in advance.

I don't have any oBd2 ADX's, I primarily use HP tuners since I invested in there interface long ago. I wasn't aware there were any specific OS ADX's available?
What interface are you using, could you use a different loging program with it? Perhaps the torque app?

[Some Fool]

I am trying to get it to work with Tunerpro RT so that I can correlate the AFR with the proper square in the VE table with data tracing ( so far I am recording the screen and wide band with my phone.. effective, but not very precise and quite convoluted ). The adx file I was given was setup to use a post-cat-o2 but I have been unable to get it to work yet.

[In-Tech]

I have not run across issues altering MAF transfer functions in nearly 20 years of tuning. Not saying it cannot happen, but it is not something I have seen in many different platforms. I mainly tune GM and Nissan.

I would not go to speed density, it is near pointless and not nearly as accurate. A recalibrated MAF transfer is far more accurate then the best speed density. I had two Dodges that never could achieve accurate fueling, atleast not like a GM or Nissan.

I also converted my TBI to an 85mm MAF years ago.

Hiya Fast, thanks for the reply. I think we are both on the same page and you obviously know how tricky MAF calibration can be. I am with you on a MAF calibration done correctly is much better than speed density. Of course if we can provide good blending for both, it does offer some redundant qualities if one fails. I mainly do GM, like you, and on the occasions I have to do a Ford(MAF only garbage) or a Dodge(SD even worse garbage) it's amazing how bad these things are and can still get thru CARB testing when stock or with somebody's(Rousch, SCT, many many others).

I grew up on SD tuning(early 90's), so, it doesn't bother me but MAF is king IMO.

I get a lot of tunes to do that someone else has completely screwed up the driveability. Many have spent a Lot of money and the MAF tune makes all the power, and can't drive at all at part throttle on different days, because they got into the maf tables figuring a percentage here a percentage there works fine. Plenty of times I just look at the MAF table(even on Fords) and just put it back to stock(if it has the range) and start over from stock. Fix the tube, or, stock MAF and go, Yuck.

Anyway, good to have a talk :)

[Fast355]

Hiya Fast, thanks for the reply. I think we are both on the same page and you obviously know how tricky MAF calibration can be. I am with you on a MAF calibration done correctly is much better than speed density. Of course if we can provide good blending for both, it does offer some redundant qualities if one fails. I mainly do GM, like you, and on the occasions I have to do a Ford(MAF only garbage) or a Dodge(SD even worse garbage) it's amazing how bad these things are and can still get thru CARB testing when stock or with somebody's(Rousch, SCT, many many others).

I grew up on SD tuning(early 90's), so, it doesn't bother me but MAF is king IMO.

I get a lot of tunes to do that someone else has completely screwed up the driveability. Many have spent a Lot of money and the MAF tune makes all the power, and can't drive at all at part throttle on different days, because they got into the maf tables figuring a percentage here a percentage there works fine. Plenty of times I just look at the MAF table(even on Fords) and just put it back to stock(if it has the range) and start over from stock. Fix the tube, or, stock MAF and go, Yuck.

Anyway, good to have a talk :)

It is always good to discuss things with you Carl. I too started with speed density TBI/TPI and GM CCC Q-Jet.

I too have fixed vehicles for the same reason. I actually just fixed a bone stock 5.3L to LQ9 swap. Ran poorly on startup, idled like a WW2 tank, etc. Guy had paid $700 for a dyno tune and it only ran well at WOT. The shop did not even have the correct injector data in the tune. Not a huge deal at WOT but at part-throttle fueling was everywhere. I put a stock MAF cal back into it too because it had a stock airbox, stock intake tube and stock maf.

[In-Tech]

Hiya Fast, it's funny we were just talking about this.

I get a cam change guy who just came from the dyno shop a few days before. It hauls ass but can't drive it across town. I suck the file out and told him I will be in touch in a few days if I can help.

Holy fockin crapola.


Power Enrich Fuel Equiv. Ratio Vs. RPM

RPM Eq. Ratio
0 1.260
250 1.260
500 1.260
750 1.260
1000 1.295
1250 1.315
1500 1.296
1750 1.276
2000 1.260
2250 1.310
2500 1.310
2750 1.310
3000 1.310
3250 1.451
3500 1.451
3750 1.486
4000 1.486
4250 1.486
4500 1.486
4750 1.510
5000 1.510
5250 1.510
5500 1.510
5750 1.510
6000 1.510
6250 1.510
6500 1.510
6750 1.510
7000 1.510
7250 1.510
7500 1.510
7750 1.510
8000 1.510


MAF Sensor Air Flow Vs. Output Frequency - Low

Hz gm/sec
0 0.000
150 0.776
300 1.063
450 1.349
600 1.636
750 1.922
900 2.208
1050 2.571
1200 3.008
1350 3.522
1500 4.111
1650 4.776
1800 5.596
1950 6.524
2100 7.601
2250 8.694
2400 10.154
2550 11.604
2700 13.217
2850 15.005
3000 16.826
3150 18.971
3300 21.631
3450 24.375
3600 27.005
3750 30.191
3900 33.179
4050 36.450
4200 39.681
4350 44.158
4500 47.974
4650 52.450
4800 56.100
4950 62.110
5100 66.817
5250 72.034
5400 77.879
5550 84.013
5700 90.434
5850 97.143
6000 104.187
6150 111.576
6300 119.283
6450 127.308
6600 135.652
6750 144.468
6900 153.846
7050 163.656
7200 173.896
7350 184.567
7500 195.668


MAF Sensor Air Flow Vs. Output Frequency - High

Hz gm/sec
7650 207.188
7800 219.126
7950 231.488
8100 244.275
8250 257.487
8400 271.480
8550 286.121
8700 301.342
8850 317.143
9000 333.523
9150 350.483
9300 368.023
9450 385.563
9600 403.103
9750 420.643
9900 438.184
10050 455.724
10200 473.264
10350 490.804
10500 508.344
10650 525.884
10800 543.424
10950 560.964
11100 578.504
11250 596.044
11400 613.584
11550 631.124
11700 648.664
11850 666.204
12000 683.744
12150 701.284
12300 718.824
12450 736.364
12600 753.904
12750 771.444
12900 788.984
13050 806.525
13200 824.065
13350 841.605
13500 859.145
13650 876.685
13800 894.225
13950 911.765
14100 929.305
14250 946.845
14400 964.385
14550 981.925
14700 999.465
14850 1017.005
15000 1034.545


OMFG, he had been into the MAF table like he was a Ford guy, the he PE corrected wide open throttle to "fix" his fack. Besides all his other f'ups, I threw the file away and started from stock so I could fix it.

Example of a couple things :)


Fixed

Power Enrich Fuel Equiv. Ratio Vs. RPM

RPM Eq. Ratio
0 1.180
250 1.180
500 1.180
750 1.180
1000 1.180
1250 1.180
1500 1.180
1750 1.180
2000 1.180
2250 1.180
2500 1.180
2750 1.180
3000 1.180
3250 1.180
3500 1.180
3750 1.180
4000 1.180
4250 1.180
4500 1.180
4750 1.180
5000 1.180
5250 1.180
5500 1.180
5750 1.180
6000 1.180
6250 1.180
6500 1.180
6750 1.180
7000 1.180
7250 1.180
7500 1.180
7750 1.180
8000 1.180


MAF Sensor Air Flow Vs. Output Frequency - Low

Hz gm/sec
0 0.133
150 0.133
300 0.133
450 0.133
600 0.133
750 0.133
900 1.035
1050 1.778
1200 2.412
1350 2.989
1500 3.561
1650 4.179
1800 4.892
1950 5.722
2100 6.682
2250 7.782
2400 10.186
2550 12.590
2700 14.995
2850 17.183
3000 18.833
3150 19.616
3300 23.508
3450 26.507
3600 29.718
3750 32.162
3900 37.158
4050 40.582
4200 44.594
4350 48.470
4500 53.165
4650 57.727
4800 62.643
4950 67.510
5100 73.626
5250 80.031
5400 86.745
5550 93.794
5700 101.202
5850 108.997
6000 117.208
6150 125.865
6300 134.996
6450 144.631
6600 154.789
6750 165.475
6900 176.684
7050 188.418
7200 200.674
7350 213.451
7500 229.018


MAF Sensor Air Flow Vs. Output Frequency - High

Hz gm/sec
7650 242.977
7800 257.488
7950 269.910
8100 282.754
8250 299.051
8400 312.863
8550 330.133
8700 344.324
8850 358.672
9000 377.055
9150 396.285
9300 416.082
9450 435.918
9600 455.266
9750 473.594
9900 490.367
10050 505.066
10200 538.938
10350 563.039
10500 587.859
10650 613.414
10800 639.719
10950 666.773
11100 694.594
11250 723.195
11400 752.578
11550 782.766
11700 813.766
11850 845.578
12000 878.227
12150 911.711
12300 946.055
12450 981.266
12600 1017.344
12750 1054.313
12900 1092.172
13050 1130.953
13200 1170.641
13350 1211.266
13500 1252.828
13650 1295.328
13800 1338.813
13950 1383.266
14100 1428.688
14250 1475.109
14400 1522.547
14550 1571.000
14700 1620.484
14850 1671.000
15000 1722.563

[Fast355]

Hiya Fast, it's funny we were just talking about this.

I get a cam change guy who just came from the dyno shop a few days before. It hauls ass but can't drive it across town. I suck the file out and told him I will be in touch in a few days if I can help.

Holy fockin crapola.


Power Enrich Fuel Equiv. Ratio Vs. RPM

RPM Eq. Ratio
0 1.260
250 1.260
500 1.260
750 1.260
1000 1.295
1250 1.315
1500 1.296
1750 1.276
2000 1.260
2250 1.310
2500 1.310
2750 1.310
3000 1.310
3250 1.451
3500 1.451
3750 1.486
4000 1.486
4250 1.486
4500 1.486
4750 1.510
5000 1.510
5250 1.510
5500 1.510
5750 1.510
6000 1.510
6250 1.510
6500 1.510
6750 1.510
7000 1.510
7250 1.510
7500 1.510
7750 1.510
8000 1.510


MAF Sensor Air Flow Vs. Output Frequency - Low

Hz gm/sec
0 0.000
150 0.776
300 1.063
450 1.349
600 1.636
750 1.922
900 2.208
1050 2.571
1200 3.008
1350 3.522
1500 4.111
1650 4.776
1800 5.596
1950 6.524
2100 7.601
2250 8.694
2400 10.154
2550 11.604
2700 13.217
2850 15.005
3000 16.826
3150 18.971
3300 21.631
3450 24.375
3600 27.005
3750 30.191
3900 33.179
4050 36.450
4200 39.681
4350 44.158
4500 47.974
4650 52.450
4800 56.100
4950 62.110
5100 66.817
5250 72.034
5400 77.879
5550 84.013
5700 90.434
5850 97.143
6000 104.187
6150 111.576
6300 119.283
6450 127.308
6600 135.652
6750 144.468
6900 153.846
7050 163.656
7200 173.896
7350 184.567
7500 195.668


MAF Sensor Air Flow Vs. Output Frequency - High

Hz gm/sec
7650 207.188
7800 219.126
7950 231.488
8100 244.275
8250 257.487
8400 271.480
8550 286.121
8700 301.342
8850 317.143
9000 333.523
9150 350.483
9300 368.023
9450 385.563
9600 403.103
9750 420.643
9900 438.184
10050 455.724
10200 473.264
10350 490.804
10500 508.344
10650 525.884
10800 543.424
10950 560.964
11100 578.504
11250 596.044
11400 613.584
11550 631.124
11700 648.664
11850 666.204
12000 683.744
12150 701.284
12300 718.824
12450 736.364
12600 753.904
12750 771.444
12900 788.984
13050 806.525
13200 824.065
13350 841.605
13500 859.145
13650 876.685
13800 894.225
13950 911.765
14100 929.305
14250 946.845
14400 964.385
14550 981.925
14700 999.465
14850 1017.005
15000 1034.545


OMFG, he had been into the MAF table like he was a Ford guy, the he PE corrected wide open throttle to "fix" his fack. Besides all his other f'ups, I threw the file away and started from stock so I could fix it.

Example of a couple things :)


Fixed

Power Enrich Fuel Equiv. Ratio Vs. RPM

RPM Eq. Ratio
0 1.180
250 1.180
500 1.180
750 1.180
1000 1.180
1250 1.180
1500 1.180
1750 1.180
2000 1.180
2250 1.180
2500 1.180
2750 1.180
3000 1.180
3250 1.180
3500 1.180
3750 1.180
4000 1.180
4250 1.180
4500 1.180
4750 1.180
5000 1.180
5250 1.180
5500 1.180
5750 1.180
6000 1.180
6250 1.180
6500 1.180
6750 1.180
7000 1.180
7250 1.180
7500 1.180
7750 1.180
8000 1.180


MAF Sensor Air Flow Vs. Output Frequency - Low

Hz gm/sec
0 0.133
150 0.133
300 0.133
450 0.133
600 0.133
750 0.133
900 1.035
1050 1.778
1200 2.412
1350 2.989
1500 3.561
1650 4.179
1800 4.892
1950 5.722
2100 6.682
2250 7.782
2400 10.186
2550 12.590
2700 14.995
2850 17.183
3000 18.833
3150 19.616
3300 23.508
3450 26.507
3600 29.718
3750 32.162
3900 37.158
4050 40.582
4200 44.594
4350 48.470
4500 53.165
4650 57.727
4800 62.643
4950 67.510
5100 73.626
5250 80.031
5400 86.745
5550 93.794
5700 101.202
5850 108.997
6000 117.208
6150 125.865
6300 134.996
6450 144.631
6600 154.789
6750 165.475
6900 176.684
7050 188.418
7200 200.674
7350 213.451
7500 229.018


MAF Sensor Air Flow Vs. Output Frequency - High

Hz gm/sec
7650 242.977
7800 257.488
7950 269.910
8100 282.754
8250 299.051
8400 312.863
8550 330.133
8700 344.324
8850 358.672
9000 377.055
9150 396.285
9300 416.082
9450 435.918
9600 455.266
9750 473.594
9900 490.367
10050 505.066
10200 538.938
10350 563.039
10500 587.859
10650 613.414
10800 639.719
10950 666.773
11100 694.594
11250 723.195
11400 752.578
11550 782.766
11700 813.766
11850 845.578
12000 878.227
12150 911.711
12300 946.055
12450 981.266
12600 1017.344
12750 1054.313
12900 1092.172
13050 1130.953
13200 1170.641
13350 1211.266
13500 1252.828
13650 1295.328
13800 1338.813
13950 1383.266
14100 1428.688
14250 1475.109
14400 1522.547
14550 1571.000
14700 1620.484
14850 1671.000
15000 1722.563



Just fixed a stock LQ9 myself that a local dyno shop screwed up badly. Made good power at WOT, but idled and drove terribly. 4L60E was shifting terribly because they axed all torque management out of it. They claimed it had bad knock sensors. Still had the 5.3L knock sensor calibration that they just Zerod out its ability to retard timing.

[bobcratchet555]

I am NOT wrong! I have personally witnessed that style MAF as well as the earlier LT1/Vortec/LS1 MAFs do the same thing. The one in particular, I swapped the stock intake tube and box back on to and proved the MAFs (tried 2 different ones) were just fine. I then stuck an 04 LS1 Vette MAF curve in it and it worked with only slight adjustments needed. 5.3L with a 10" long straight 3.75" coupler off the throttle body into a cone filter on a vehicle with very limited engine compartment space. GM uses that same MAF with numerous different airflow tables.

If what you said is correct, this would not happen. The only thing wrong here even was a missing air cleaner element. Fuel trims went +20% the moment the stock air box was mistakingly installed without a filter. Fuel trims were a little off with the open sensor end as well(probably from the mechanical fan blowing air across the sensor) Filter in place and they were sitting near perfect.
https://youtu.be/m-qJ58scPJE

My 4" cartidge MAF has a slightly modified GM Performance Crate 525 HP LS3 MAF curve but I need to add a flow straightner to it.

if nots not a lot of work, would you mind sharing a file with this MAF curve?

i plan to run the cartridge MAF (LS7?) in a 4" tube and would be tickled to have a base curve to start tuning with. Thanks.

[Fast355]

if nots not a lot of work, would you mind sharing a file with this MAF curve?

i plan to run the cartridge MAF (LS7?) in a 4" tube and would be tickled to have a base curve to start tuning with. Thanks.

Just threw it into an Open Office file. Should be easier to open generically than an BIN, HPT or Tunercats file for some.

[bobcratchet555]

Just threw it into an Open Office file. Should be easier to open generically than an BIN, HPT or Tunercats file for some.

much appreciated, thank you

[Some Fool]

To log WBo2, you should connect the 0-5vlt analog signal to blue pin 55. This is egr position sensor .
You need to have commanded egr to 0, disable egr codes, and zero out egr fuel reduction and egr spark tables.
If you are keeping fuel trims on, all you can do is aim for 0 trim. If you go open loop, you can tune to 14.7 on your gauge, then turn cl back on and tune O2 swing points to match almost no trim.
If you add 10%, and the fuel trims take out 10%, then you add another 10%, fuel trims will now want to take out 20%, the further you get from true, the longer it takes for it to learn what's right.

Does anyone have an .adx file for OS 12212156 that they are willing to share to make this possible? Please
Thank you in advance.
Some Fool

[Some Fool]

Update: I was able to get the VE and MAF bins dialed in quite close however as soon as I turn everything back on and the truck starts using the O2 information it goes to 15.8-16.1:1 AFR.. The trims are about %5 ( both banks ) and the O2s are swinging between 0.3V and 1.0V.. All of the spark plugs are showing lean ( to my untrained eye ) and all of the injectors are firing ( all made a significant change when unplugged ). I have drenched this thing several times trying to find a vacuum leak ( I would think that it would not behave in the VE only tune if it were leaking? ). Adjusting the switching points in both directions had no effect. What am I missing? Two bad 02s ( seemed fine in a bench test with torch and a DMM )? :mad1:

[steveo]

a narrowband o2 can't really target 15.8:1, so if your trims are truly landing you at 15.8:1:

- messed something up in your bin regarding o2 configuration
- o2(s) is(are) bad
- o2 wiring or ground or something is bad
- the 15.8-16.1:1 has a measurement error.

my hunch says its the last one