Got a handle on VE, but MAF has me puzzled

[Firebirdjones]

I ran a couple of datalogs today, with the MAF disabled as per instruction, and using the LTFT histogram and moderate to light throttle. I found most everything +4 and +5 so I made the appropriate changes in the VE table and made another log etc....
After 3 tries I had the LTFT histogram looking pretty nice on the lower half (under 3,500 rpms) with 0's most of it and a few -1 with only a couple of -2.

I was happy with that so I re-enabled the MAF sensor with my new VE table and made another datalog run,,,,now the LTFT histogram is +12 and +14 in most places. It's showing pretty lean.
What up with that? Do I need to play with the MAF tables now or something? I really appreciate any insight on this. Thanks, Larry.

[EC_Tune]

Yep, MAF is usually off after you tune the VE. Make sure you're logging MAF Hz on the table view or you won't get any MAF info in the histograms.

EC

[SSJoe15]

I have the exact same problem. and i do not understand your answer if you could respond as if you were trying to explain it to a 1st grader cause that is about the level that i am at. thanks, joe

forgot to add: just installed long tubes, ls6 intake and ported throttle body

[Firebirdjones]

I think that is my problem EC tune,,,I now have the MAF enabled and I am logging. But I don't think I am logging as you describe with MAF HZ on the table view.
I am not sure how to go about that. I did manage to log LTFT's and like I said, it was lean everywhere. My problem is, I cannot figure out how to apply the LTFT histogram to the MAF Table,,,because the MAF table is a long skinny table that is not setup like the VE table is.

It was simple to do the VE table, you could go box to box if you had to,,,very simple. But the MAF table is not setup like this.
Since the MAF table is long and skinny and I cannot tell which block needs attention,,,I took an average from my LTFT,,,(in this case I took 8%) and I just added 8% accross the entire MAF table for giggles. Another datalog of LTFT's and now some of the blocks are too rich I wish there was a MAF table similar to the VE table so it would be easy to transfer the info.
There has to be something stupid I am missing here. Larry.

[2000C-5]

I think that is my problem EC tune,,,I now have the MAF enabled and I am logging. But I don't think I am logging as you describe with MAF HZ on the table view.
I am not sure how to go about that. I did manage to log LTFT's and like I said, it was lean everywhere. My problem is, I cannot figure out how to apply the LTFT histogram to the MAF Table,,,because the MAF table is a long skinny table that is not setup like the VE table is.

It was simple to do the VE table, you could go box to box if you had to,,,very simple. But the MAF table is not setup like this.
Since the MAF table is long and skinny and I cannot tell which block needs attention,,,I took an average from my LTFT,,,(in this case I took 8%) and I just added 8% accross the entire MAF table for giggles. Another datalog of LTFT's and now some of the blocks are too rich I wish there was a MAF table similar to the VE table so it would be easy to transfer the info.
There has to be something stupid I am missing here. Larry.

You were close, you just went the wrong way.

You need to log LTFT in Hz, so that it matches the MAF histogram. Here is mine and how the histo should be set up.

[Firebirdjones]

I knew it was something silly. Thanks for that picture. I will set that up tomorrow and go for a run and see what I get. Thanks again.

[Firebirdjones]

I think that is what EC tune was telling me and I couldn't grasp it,,,until I saw the picture You guys will be glad I am around so you have someone to pick on

[EC_Tune]

LOL We try hard not to pick on the noobies. We also try to remember we were noobies once too.

[Bob Wiley]

You were close, you just went the wrong way.

You need to log LTFT in Hz, so that it matches the MAF histogram. Here is mine and how the histo should be set up.

When you add/change a histogram, do you have to save it as a new config file? I'm just learning and trying to deal with what I see in my logs (most of the time LTFT is +25). I know this means I'm no where near having a proper tune.

[EC_Tune]

You don't have to save as new but you can.

[2000C-5]

When you add/change a histogram, do you have to save it as a new config file?

Like EC said, you don't have to. I made up a config file for VE tuning one for MAF/WOT tuning, and another for closed loop.

I'm just learning and trying to deal with what I see in my logs (most of the time LTFT is +25). I know this means I'm no where near having a proper tune.

I'd say...that's really lean. You should richen up the whole VE table about 10% right off the bat.

[SSJoe15]

Sorry for maybe beating a dead horse but i cannot for the life of me get the histogram that you showed to work for my car or computer could someone tell me what i am missing.

it just tells me the you dont have something right or your histogram is not set up correctly. it will show the chart and then the instant that i try to start a log it disappears. thanks in advance, joe

[sprayin'99ss]

Sorry for maybe beating a dead horse but i cannot for the life of me get the histogram that you showed to work for my car or computer could someone tell me what i am missing.

it just tells me the you dont have something right or your histogram is not set up correctly. it will show the chart and then the instant that i try to start a log it disappears. thanks in advance, joe

I have a thread about this very thing in the vcm suite help forum at the top of the first forum selection page "need help with histogram". Very good instructions, I haven't tried it yet but feel pretty confident I have it set up right now! I think (vets please correct me if i am wrong) you need the correct config file too. i saved the config file from the sticky at the top of this forum, and also saved 5 liter Eaters histogram file from the other MAF tuning thread from Firebird in this forum. i then opened the config file and imported the histogram. i am pretty sure that'll work when you start your next scan! Again if the senior tuners see anything I am explaining wrong please correct me!

[Bob Wiley]

Like EC said, you don't have to. I made up a config file for VE tuning one for MAF/WOT tuning, and another for closed loop.

I see. I was thinking of leaving the default one as is, and then making up new config files for different things, just like you mentioned. Rather than just trying and possibly screwing something up, I thought I'd ask first. Thanks.

I'd say...that's really lean. You should richen up the whole VE table about 10% right off the bat.

I was thinking that should be my first step, but as mentioned above, I wanted to double check first. I notice on my LTFT histograms that those +25 numbers are concentrated in only certain areas, especially in two of the RPM columns and for quite a number of MAP rows for those two columns. So, I assume I should increase those corresponding cells in the VE table. I guess my ported MAF sensor caused the really lean condition (ported long before I got the HP software).

[2000C-5]

Sorry for maybe beating a dead horse but i cannot for the life of me get the histogram that you showed to work for my car or computer could someone tell me what i am missing.

it just tells me the you dont have something right or your histogram is not set up correctly. it will show the chart and then the instant that i try to start a log it disappears. thanks in advance, joe

Open the "Table Display" and make sure that you are logging MAF in Hz. You will have to add it in. Right click on an empty space and select insert, choose MAF Hz. It should work then. Anything that you are logging must be in the Table Display for it to work in the histograms.

[2000C-5]

I see. I was thinking of leaving the default one as is, and then making up new config files for different things, just like you mentioned. Rather than just trying and possibly screwing something up, I thought I'd ask first. Thanks.

It won't let you change the default one even if you try.



I was thinking that should be my first step, but as mentioned above, I wanted to double check first. I notice on my LTFT histograms that those +25 numbers are concentrated in only certain areas, especially in two of the RPM columns and for quite a number of MAP rows for those two columns. So, I assume I should increase those corresponding cells in the VE table. I guess my ported MAF sensor caused the really lean condition (ported long before I got the HP software).

Your MAF shouldn't be causing any lean conditions if you are tuning VE. Your MAF should be unplugged or turned off (speed density) via software to tune VE. Reset your trims before you start VE tuning (in VCM Controls).

[SSJoe15]

THANKS. i will take a look tomorrow and see what i still dont know. joe

[Bob Wiley]

Your MAF shouldn't be causing any lean conditions if you are tuning VE. Your MAF should be unplugged or turned off (speed density) via software to tune VE. Reset your trims before you start VE tuning (in VCM Controls).

Well, I haven't even touched the VE tables. I've just been logging data with everything still connected. So, I should try tuning in SD mode first? Even without a wideband? Sorry for the dumb noob questions, I'm just taking baby steps.

[mrr23]

to tune the VE table, you have to remove the MAF from the equation. i'm doing my VE without a wideband right now as well. i use the STFT histogram to modify the VE table. on my first shot, i got it to 0% in the cells i hit today. i'll log again tomorrow to see if it stays within 4% before i move onto the MAF.

[Bob Wiley]

OK, I see. I'll start there. Thanks.