ECMlink Diagnosing a Sputter

[EvoSlapper]

My car's profile is up-to-date. There is a sputtering at idle and when cruising. I am not seeing it under WOT and full boost. I was thinking it was a boost/vac leak but I've since sorted those and I am still seeing it. Idle is a little rough as well.

I picked up this GSX a few months back. Most of the work was done in 2016-2017 and then it sat for most of the time. Since I've bought it I've replaced the MAP sensor and a few parts on the cold side to fix a few boost leaks.

AFR seems to be good across the board - high 13s to low 15s when cruising and mid 11s under full boost. EGTs seem high, though. Level cruising I am seeing 1,200-1,300, uphill cruising 1,300-1,400, and WOT 1,500 (a little more in summer temps). The gauge reads to 1,600 but I have not seen it pegged. If these temps are high could this be timing related?

I have logs that I can share as well as my current tune and direct access files but I am not seeing the option to upload a file. Is this because I am still a probationary member?

 

[steve]

I have logs that I can share as well as my current tune and direct access files but I am not seeing the option to upload a file. Is this because I am still a probationary member?

It's because you use the Add Photos button, confusing but that's how it works.

 

[EvoSlapper]

Got it thank you!

Files attached.

 

[jed344]

Have you been tuning the car or is this all from before? The tune has been heavily modified. There is quite a few things i personally do not like the look of i see in it.

 

[EvoSlapper]

Have you been tuning the car or is this all from before? The tune has been heavily modified. There is quite a few things i personally do not like the look of i see in it.

I have been making some changes to the tune that was already uploaded. Very minimal and with the guidance of the tutorials on here.

What don’t you like?

 

[jed344]

I have been making some changes to the tune that was already uploaded. Very minimal and with the guidance of the tutorials on here.

What don’t you like?

So the Bulk of the tune was from before then? This tune was done for this car specifically with the same mods? I ask just due to how much has been changed. When in direct access everything in bold has been modified. Most is not changed that much and if it was done for this exact car and mods and what it wanted then fine. The things i see in the DA tables that look very strange are.
1. The injector battery adjust values, i have never seen a injector that at 9v vs 12v is that similar in dead time. Without more data or logs i cannot say its wrong but it looks very different then i am used to.
2. The open loop max and min air fuel target tables look like a modified stock 1g table maybe. I cannot remember how they look off hand. This is not causing ur issue just a semi changed stock table i think.
3. The max and min octane timing tables are interesting. Likely will not knock on them but leaves a lot on the table. Honestly looks like some miss clicks when who ever did them made them.
4. The Speed density table. I know for a fact your not at 99+ ve at 7,000rpm. The bigger issue is its not smooth from idle to cruising area. The large jump in cells and overall not being smooth can cause issues. Often the tool will recommend values and even though those values may be correct for that exact cell, large jumps often cause things you can feel driving the car as it swing's wildly quickly. You want to smooth them. So yes you may be making some cells not exact per say but when everything is smooth and no wild jumps the car drives better.
5. I see you have a user defined map sensor being used. Do you have this set correctly? I think your mod list said a aem 4 bar? I was not aware they made one but either way long as that is configured correctly it will work.
I ask about the map sensor as this is critical on a SD car as if this is not logging correctly it will throw everything wildly off.
There is other thing's but these are the main things off the bat.

 

[EvoSlapper]

So the Bulk of the tune was from before then? This tune was done for this car specifically with the same mods? I ask just due to how much has been changed. When in direct access everything in bold has been modified. Most is not changed that much and if it was done for this exact car and mods and what it wanted then fine. The things i see in the DA tables that look very strange are.
1. The injector battery adjust values, i have never seen a injector that at 9v vs 12v is that similar in dead time. Without more data or logs i cannot say its wrong but it looks very different then i am used to.
2. The open loop max and min air fuel target tables look like a modified stock 1g table maybe. I cannot remember how they look off hand. This is not causing ur issue just a semi changed stock table i think.
3. The max and min octane timing tables are interesting. Likely will not knock on them but leaves a lot on the table. Honestly looks like some miss clicks when who ever did them made them.
4. The Speed density table. I know for a fact your not at 99+ ve at 7,000rpm. The bigger issue is its not smooth from idle to cruising area. The large jump in cells and overall not being smooth can cause issues. Often the tool will recommend values and even though those values may be correct for that exact cell, large jumps often cause things you can feel driving the car as it swing's wildly quickly. You want to smooth them. So yes you may be making some cells not exact per say but when everything is smooth and no wild jumps the car drives better.
5. I see you have a user defined map sensor being used. Do you have this set correctly? I think your mod list said a aem 4 bar? I was not aware they made one but either way long as that is configured correctly it will work.
I ask about the map sensor as this is critical on a SD car as if this is not logging correctly it will throw everything wildly off.
There is other thing's but these are the main things off the bat.

Yes, the map was done specific to the mods currently on the car. I haven’t messed with much and very minor adjustments at that (trying to smooth things out). The injector values I don’t really understand. The only thing I would adjust was the dead time trying to smooth out the idle.

I do see that he loaded an Evo 8/9 map. This was in the notebook he gave me with the car.

The 4 bar MAP is the AEM style. It’s not an AEM sensor. I’ve inputted the min and max values per the install instructions that came with it.

Would I be better off wiping this current map and starting over?

 

[jed344]

What injectors are in the car and what is base fuel pressure. You do not need to wipe everything. I would suspect the exhaust temps are hot at wide open looking at the timing table. Low timing advance leads to hot egt's.

 

[EvoSlapper]

What injectors are in the car and what is base fuel pressure. You do not need to wipe everything. I would suspect the exhaust temps are hot at wide open looking at the timing table. Low timing advance leads to hot egt's.

You are correct about EGTs. Now that it’s much cooler I see them in the 1,400-1,500 range at WOT. In the summer they were getting closer to 1,600 (which is max for my gauge).

Currently running 950cc injectors and base fuel pressure is 42.5psi.

 

[jed344]

I would recommend if you do not have a sheet or are able to find the data for the inj offset chart that you return those values to stock and just use the dead time value then. Then use the calculation to get a fuel global to start with. Just because say the wideband is in the area of the air fuel you want does not mean the tune is correct. I often see this. This leads to the ECUs idea of how much air there is being wrong but it ends up hitting the value you want. When you hit the target due to the ECU's idea of VE and adding the correct amount of fuel to hit it then that mean's it knows and always leads to better results.