WB Maf Tuning ... Questions/Logs

[2000C-5]

You need to:

- set the Engine/Fuel Control/OL & CL/Closed Loop Closed Loop Enable/ECT vs IAT to 284* across the board. This will put you in open loop along with setting the MAF fail freq to 0.

- on the same page as above, you want to disable LTFT

- also on this same page, in Open Loop/EQ Ratio, set all to 1.00 or I just set the ones from 140* and up to 1.00 (this will command 14.63 or stoich)
This step can be done several ways too. You can leave it as is if you want or change it to 1.13 which will command 13.0 AFR, because it doesn't really matter what you are commanding, because the % error will still be the same. After going back to Closed Loop this table isn't used anymore.

- in Engine/Fuel Control/Fuel Cutoff set DFCO enable temp to 284*

- in Engine/Fuel Control/COT, Lean Cruise set COT to disable

- in Eng. Diag/Airflow set MAF fail freq to 0 (you should also unplug the MAF if you can, but you won't be able to because your IAT is wired in the same plug, they are seperate in the earlier C-5s)

Now go log. Make sure you log VE for AFR, commanded AFR, and AFR percent error. I log first and then change the cell hits required to 25 for the percent error. Right click/Copy the percent error histogram, open Editor and use the paste special/multiply by % to the Engine/Airflow/General Airflow/Main VE/Primary table. Then, if you have a 1997-2000 C-5, copy the even numbered MAP lines to the secondary VE table by using the old copy/paste method. Save and "write calibration only" to the PCM. Drive and see where you are.

After this, reset the MAF fail back to 14000 (leave everything else as is for now) and do the same thing for the MAF tables using MAF vs Output Freq (Hz) histograms instead of the VE histograms.

How's it look now?

[Dirty Howie]

Yea, oops...I forgot you don't have the secondary VE tables.

I didn't mean to take it to the track with you. When you start logging the VE tables you'll see what I mean. It's not like logging for MAF freq.

Right.

No problem......I was pretty sure I only saw one table when I was mucking around in there.

I think I understand that the VE tuning is slow and easy...so the computer should be safe....and that you want to see cells hit and counts..right??

......the problem is you never know when a Porche GT might show up that needs to be spanked


DH

[2000C-5]

No problem......I was pretty sure I only saw one table when I was mucking around in there.

I think I understand that the VE tuning is slow and easy...so the computer should be safe....and that you want to see cells hit and counts..right??

......the problem is you never know when a Porche GT might show up that needs to be spanked


DH

Hopefully you are talking about a GT3 (~3000 lbs, 400+ hp). If you are talking about a Carrera GT (~3000 lbs, 600+ hp) you're gettin' a little cocky. You'll need more than HP Tuners to spank that.

[Dirty Howie]

Hopefully you are talking about a GT3 (~3000 lbs, 400+ hp). If you are talking about a Carrera GT (~3000 lbs, 600+ hp) you're gettin' a little cocky. You'll need more than HP Tuners to spank that.

GT3 is what I meant Like to pick these off at the track


DH

[Dirty Howie]

I'm going to post this in another thread too as I'm not sure who will be around to answer these questions....sorry!!!

I started to change settings in my tune in preparation to log VE on the way home but have some questions.

First: does it matter that current tune has some maf table tuning already??
Should I go back to the tune before I started the maf tuning??????

Second: disableing the LTFT: I set min ECT to 284 and max ECT to 0
Is this correct???? instructions just say diable LTFT (I didn't see a
disable button)

Third: my COT was ALREADY diabled. Whats up with that????????

Fourth: what exacty do I do in the DTC so that SES doesn't come on???

Here is the tune I am preparing for the VE logging. Please check it out for me....thanks!!!


DH

[5_Liter_Eater]

Any MAF tuning would have just edited the MAF table. When you are VE tuning you disable the MAF so it doesn't matter. No need to go back to the tune you had prior to MAF tuning.

It looks like your LTFT's are certainly disabled. There is also the VCM Controls in the scanner "Fuel Trim Learn - Off" just to be triple sure.

COT is not disabled in any stock LS1 tune so I donno what to say there.

Your MAF Fail High is good. To keep the SES light from illuminating, uncheck the SES Enable on P0103 (I think). If that doesn't work then re-check that box and set the error mode to No MIL Light. Just don't set it to No Error Reported or the MAF will not fail and you will not be in SD.

[Dirty Howie]

Any MAF tuning would have just edited the MAF table. When you are VE tuning you disable the MAF so it doesn't matter. No need to go back to the tune you had prior to MAF tuning.

It looks like your LTFT's are certainly disabled. There is also the VCM Controls in the scanner "Fuel Trim Learn - Off" just to be triple sure.

COT is not disabled in any stock LS1 tune so I donno what to say there.

Your MAF Fail High is good. To keep the SES light from illuminating, uncheck the SES Enable on P0103 (I think). If that doesn't work then re-check that box and set the error mode to No MIL Light. Just don't set it to No Error Reported or the MAF will not fail and you will not be in SD.

I think I am going to be more comfortable going back to tune before messing with the Maf table. I am getting some pinging now and want to reset my PE to 1.14 anyways. Its certainly no big deal as I have the WB permanently installed and I just have my one car to worry about.

AND all settings are the same when doing VE or MAF except that maf is enabled for maf tuning and disabled when doing VE....right??....which I didn't have at the time of maf tuning.

My tune is NOT stock ..... I wonder if my highflow cats on the Kooks headers are considered not real cats


DH

[5_Liter_Eater]

Closed loop and fuel trims will still be disabled for MAF tuning. Just re-enable the MAF and put the SES back. Also you wil not be altering the VE table when tuning the MAF.

Fattening up a little is no big deal. You could even go a little fatter than 1.13. Once you nail the AFR, IE, whatever you are commanding is what you get you can move the PE up or down and see what results it yields. No need to tune to the ragged edge right now.

If your tune was not stock to begin with then that explains your COT being disabled. No worries.

[Dirty Howie]

Closed loop and fuel trims will still be disabled for MAF tuning.

This is what I am trying to say: I did not disable closed loop or fuel trims when I did the maf tuning !!!!!!!!!

Thats why I thought I might as well start over as its certainly no big deal....I have all my tunes saved.

Thanks for hanging with me on this.....


DH

[2000C-5]

Fourth: what exacty do I do in the DTC so that SES doesn't come on???

You can also do this in VCM controls. It will just turn the light off.

[Dirty Howie]

You can also do this in VCM controls. It will just turn the light off.

I went ahead and did everything in the list and logged all the way home without going WOT (this was very hard )

Don't you have to RESET the LTFT as well as turn them off as I have read elswhere?????

I will post the log later........

****** I didn't get any SES light?????? But when I checked the DIC P0103 was set to C?????******


DH

[Dirty Howie]

Well here is my first log. And the tune with settings for logging of VE.

Please look at the CHART

AFR is consistantly richer than commanded except for:
A. startup (before car fully warmed)
B. during deceleration

Should I wait till car is full warmed before logging??
Shouldn't DFCO disabeled have prevented AFR from reading LEAN

Should I use this log??? and copy % error and flash. Or should I filter these very high lean areas (and if so how do I do that???)

Only went into PE once at frame 12800

Anybody around today to check this for me???????


DH

[MMGT1]

Hey Howie. I haven't gotten into VE tuning yet myself but be careful man. You are really LEAN!! Hopefully one of the guys can help before you drive it again...

never mind...your car evens out when it warms up. Looks like it was lean at the start and then levels out! Looks like your car needs to be warmed up before you start the scan

[Dirty Howie]

Hey Howie. I haven't gotten into VE tuning yet myself but be careful man. You are really LEAN!! Hopefully one of the guys can help before you drive it again...

never mind...your car evens out when it warms up. Looks like it was lean at the start and then levels out! Looks like your car needs to be warmed up before you start the scan

But should it be lean like that at start????.....though rich was normal at start???


DH

[MMGT1]

No, you are right! I tried to correct myself when I watched your scan again. (Second part of the post above)

[2000C-5]

Looks pretty rich to me. Most of your AFRs are in the 12s and 13s where 14.68 is commanded. I would not start tuning until the car had completely warned up. I actually drive a couple of blocks and pull over into a fire dept. parking lot and start tuning. That way everything is warmed up, oils, tranny, etc.

I would go ahead and use the log you have and see where it puts you. You should notice a pretty good difference, because most of your afrs are in the range that the WOT should be.

Use the average, set cell hits to at least 20-25 to weed out some of the cells that have very few hits, and paste it to your VE table. You will feel the results, especially in throttle response. Then just do it again until the AFR % error is all close to 0. No need to worry about the car learning. By the way, your LTFTs are still enabled, you should not have readings in the LTFT histo. It looks like the DFCO may still be on too, giving you the 20 AFR readings on decel.

EDIT: I just looked and your DFCO and LTFT are disabled, so I don't know. Hopefully someone will jump in. I'd still use it though, it won't hurt anything.

[Dirty Howie]

No need to worry about the car learning.

Are you saying I don't need to reset the ftrims using the VCM controls?

By the way, your LTFTs are still enabled, you should not have readings in the LTFT histo. It looks like the DFCO may still be on too, giving you the 20 AFR readings on decel.

EDIT: I just looked and your DFCO and LTFT are disabled, so I don't know. Hopefully someone will jump in. I'd still use it though, it won't hurt anything

Thanks for looking.....I set everything up as you outlined and confirmed by others. So how can this be??????

I will try to setup the histogram to filter out the AFR's above 17

I will definately use the VCM Controls to reset fuel trims and turn off when I do more logging tomarrow.

I get the whole process now...thanks for you help.


DH

[2000C-5]

Are you saying I don't need to reset the ftrims using the VCM controls?



Thanks for looking.....I set everything up as you outlined and confirmed by others. So how can this be??????

I will try to setup the histogram to filter out the AFR's above 17

I will definately use the VCM Controls to reset fuel trims and turn off when I do more logging tomarrow.

I get the whole process now...thanks for you help.


DH

No need to reset the fuel trims, they are supposed to be disabled, you aren't even using them. Your fuel trims are no longer a part of your tuning process. When you get your % error for VE and MAF in line, you can then re-enable your fuel trims to confirm your results.

[5_Liter_Eater]

AFR will spike lean on warmup due to the air pump. It kicks on and injects air into the exhaust stream which gives a false lean condition. But you shouldn't be tuning until you're warmed up.

Even with DFCO disabled your decel cells will still show lean. Don't worry about it, it's only in the decel cells. I think you're trying to get too fancy. You've got the concepts down. I'd use that log, all of it, just copy and paste %. Just see where it gets you.

[Dirty Howie]

Okay guys I will copy that histogram this morning and and try and get another log to compare the results......thanks for assuring me

Monday I will be able to get a couple of long (45-60 minutes) logs

But it just sems to me that those lean spikes don't make sense. And LTFT must be a factor or we wouldn't go thru the process of trying to turn them off.........

Thnaks guys !!!


DH