Cobalt Maf Tuning

[Isaak]

I am trying tot tune my MAF on my LSJ Cobalt but am really unsure about my config, the LTST + STFT x MAF to be specific.

I have read a bunch of write ups and watched some videos and was confident I had it right.

While attempting to scan, the chart is showing -1 in various maf hz, made a small difference, I then tried again but received nothing but zero's.

Any help?



MYTUNE.hpt

LSJ OPEN LOOP TUNING.hpt

cobaltlsj.Layout.xml

[cobaltssoverbooster]

i cant open the LSJ Open loop file because its in remote tuner lock.
according to your MYTUNE file you wont be functioning off the map sensor until 4000 rpm. if you wish to tune for it lower then you need to adjust the high rpm value in dynamic airflow tab to a lower rpm value.
make sure you also readjust the re-enable value to 200 rpm below whatever your high rpm value is to prevent internal coding errors.

your histogram should work fine as long as your engine temp is over 104*F. This is the point at which LTFT become active. also it should be worth noting that trims are not active during PE mode so it is recommended to add a channel filter that is based on EQ Ratio commanded. It should say something like PID(EQR Commanded) =1
this means anytime the EQ Ratio is not commanding stoich the data will be omitted since the trims go inactive and cause garbage values to be considered in your data. For EQR above 1 you will have to use your wideband.
the second thing that is worth noting is that you need to connect your scanner to the vehicle and clear fuel trims using the scanner functions after performing a flash. The LSJ doesnt always reset trims and learn cycle information when performing a flash.

[Isaak]

Thanks for the response. I am not sure why it says locked, I checked and says it is unlocked, I will try to upload it again asap.

I figured the LSJ was picky, nothing like a Grand Prix pcm that I am used to, so easy compared to this!

I am trying a few different things, hopefully something works, for now I just have the LTFT disabled as it throws a code within minutes.

I am also going to replace both 02 sensors shortly and go over the engine for any vacuum leaks.

[Isaak]

Changed upstream 02 sensor, fuel trims are acting normally again, now maybe I can actually tune them properly.

[Isaak]

A scan from a quick drive, much improved, now hopefully the work can begin to straighten the trims out.

APR23_NEW O2.hpl

[Isaak]

Did some scanning, adjusted my MAF a bit and was able to lean it out, a lot, but now I know which way to go.


APR25.hpl

APR25_BETTER FT.hpl

TEST.hpt

[cobaltssoverbooster]

you need to add a filter to your maf histogram. your maf isnt active until 4000 rpm is exceeded so the filter needs to say rpm>4000
the values its plotting below 4000 rpm are values that should be adjusted using the ve table. if you want to tune your maf for the whole rpm range then you need to do what i mentioned in post#2

im assuming your didnt change this filter because you didnt upload any new .xml files.

[Isaak]

you need to add a filter to your maf histogram. your maf isnt active until 4000 rpm is exceeded so the filter needs to say rpm>4000
the values its plotting below 4000 rpm are values that should be adjusted using the ve table. if you want to tune your maf for the whole rpm range then you need to do what i mentioned in post#2

im assuming your didnt change this filter because you didnt upload any new .xml files.

This is the filter I have attached... I used the EQ Commanded, will try it out tomorrow.

snip.JPG
MAFFILTER.JPG

[cobaltssoverbooster]

Capture.PNGyou need that and an rpm filter. so between the two put the word "and" followed by this.

you will need to change this value according to whatever you set your maf threshold to as described in post #2

[cobaltssoverbooster]

i highly suggest you do research on tuning in maf mode and speed density mode.
if you dont understand these two things, which you seem to be having a bumpy start with understand the settings of, then your going to find this process to be harder than it should be.

[Isaak]

i highly suggest you do research on tuning in maf mode and speed density mode.
if you dont understand these two things, which you seem to be having a bumpy start with understand the settings of, then your going to find this process to be harder than it should be.

I am doing as much as possible, the 3800 GP PCM was so much easier to MAF tune than this so I am relearning a bunch of things.

I'm doing baby steps.

Again, thanks, it much appreciated.