did i tune my ve correctly?

[thebeewantsboost]

does it look like i've started to tune my ve correctly? i used a log with my nb O2 stft, and lfts.... added them together and added half of that percentage to those cells in the primary ve table.
i noticed that the graph is spikey now, where before it was actually pretty smooth.
the files are
1) the log i used to tune.
2) tune before adjusting ve
3) initial ve tune.

[majorpayne317641]

You shouldn't be adding the ltft, if you are thats wrong. Take one thing at a time, do your ve first do not have the maf interfering, unplug it or turn the fail frequency to trip. When you log your ltft, copy your histogram into your ve by paste special > multiply by percent

[thebeewantsboost]

i've read so many things, that i'm just absolutely lost, i thought that was how u did it....
so... could i get a little ve tuning for dummies lesson.... do i just need to unhook the maf and log the ltft take that table and paste > mulitply by percent?

[majorpayne317641]

Ok, this is generally speaking when relating to an LS1, V6's are similar but they say that there is a slight difference for VE and MAF tuning. I think russ k's write up on v6 VE tuning is the best to look at but...

For a v8, we set the hz fail to 0 to force the MAF to fail, then depending on your preference, either disable the mil/ses light or let it shine on your dash, you can check for this code without it lighting up on your dash if you simply disable the light (NOT the dtc) and then when scanning look to see under VCM DTC's in the scanner that the MAF code is coming up.

Now assuming that you loaded the VE tune program on the car (do not use your stock file, make another copy of your stock file and label it ve tune so you dont overwrite anything). Start the scanner, reset your ltft. Go for a drive, LS1 pcm's and this can be for others too I'm guessing, take about 100 miles or 50 minutes to learn ltft's completely. Hit as many cells on your scanner for ltft as you can. Light throttle, hard load, heavy throttle, light load, all combinations in as many gears and rpm ranges as you can do but anything over 4000 in a LS1 is not necessary to log, not sure for v6's.

Now after your ride, save your scan. Call it up, if the histograms don't show any numbers after re opening a scan file, simple right click on any histogram and click load all data.

Look at your ltft histogram. This shows what the pcm is doing to adjust ltft in relation to your ve table since its relying on that information instead of the maf. If the cells are red, and positive (default cfg file) then the pcm is adding fuel to the engine if the cells are green and negative, the pcm is subtracting fuel. This is a percent by the way and your histogram takes an average of the ltft, you can see this if you click on C for counts and A for the average.

Now you copy the entire histogram table, with labels to make it easier, then you go to your main ve table right click, paste special > multiply by percent.

Basically what you are doing is adding a percentage of the ve value onto itself if you have a ltft value that is positive and subtracting a percetage of the ve value from itself if you have a ltft value that is negative. Do not confuse that with adding the average you see on the histogram with the ve table. The percent change to the ve table is what you want and that is why you use multiply by percent.

Hope this helps some, this is just a procedure I use, works great for V8's but again some guys say that 3800's only use ve tables for maf failure. Oh and your ltft's are ideal in the +4 to -4 range, if you can get them there, your good.

[murphinator]

I used ltft histo only and mulitplied by % a few times then multiplied by 1/2%

dont forget to reset your trims first and to let your car come up to temp

on a 3800 you will need to unplug the maf to fail it unless there is a secret spot i am not aware of to fail the maf - I have looked and never found a spot to do it so I just unplug it to fail it

there are a lot of different ways out there so pick one that you comprehend well and go for it just be sure to "save as" so you always have your previous tune to fall back on if you go the wrong way.

[thebeewantsboost]

thanks soooo http://www.hptuners.com/forum/newrep...1&p=201212much guys... yeah from what i read v6's really don't use the ve much... but for transient fueling, it does, it helps with the throttle response etc.

one more question... i didn't reset my ltfts before my run.... with the maf turned off. is it ok to go ahead and use this log to tune with?

i looked at a setup for a tune to get the ve info and it had alot of changes for tables that i didn't even have... so hopefully everythings good.

to disable the maf:
go to engine diagnostics >airflow> and set maf failure to 0

[majorpayne317641]

You must reset your ltft, if you don't your averages will be based on what the pcm has been averaging for however long it stores this information (since the last time that it has been reset). Therefore make sure to reset them and log a 50 minute long trip or so trying to hit all of the cells that you can in the process. Well good luck, if it works out within the 4 percent range, you should notice a car that is peppy at transient throttle conditions.

[murphinator]

to disable the maf:
go to engine diagnostics >airflow> and set maf failure to 0

just double checked and I have nothing under airflow in diagnostics tab , so all 3800's must not be created equally but thanks

[thebeewantsboost]

i've been out of the loop for a bit...
so i just need to disable the maf. reset trims, drive a while. then log...
does it matter if im in open or closed loop?
i read a write up that said to to max out the closed loop enable ect.
but i would think u would want to be in closed.
if im tuning with a wideband can i go tune all of the cells including wot? or is there even a table for that

[mayne]

dude, disabling or removing the maf puts you in SD mode.
open loop = speed density
speed density = open loop
i think that unplugging the maf is easiest. you want to be in open loop.
widebands are for HEAVY throttle
narrowbands are for cruising around NOT for WOT

my only question is... will fuel trims be learned in SD mode? I thought, no

[stomper]

Open loop DOES NOT equal SD. Have a look through the great stickies that have been posted.

[thebeewantsboost]

i know the difference in open and closed loop. closed loop is when you're car is using the o2's. so i would think u would need to be in closed loop to learn fuel trims. but i read a post saying to disable closed loop to tune ve.