'06 GTO E40 Inconsistent Fueling

[blindsquirrel]

I can think of earlier G8's that didn't match the traditional IAT curve or the one used in LS7's. I could be wrong.


But the OEM GTO and OEM LSA lid IAT sensor are the same curve.


If anyone else is reading the values and the axis's must be copied over.

The two tables just have different resolution at different locations, that's why they look so different. But the span is near identical, differences are likely just different teams doing the calibrations and using different levels of precision. The little thermistors inside are the same so you could exchange one table axis+data for the other and nothing would change, not that'd be detectable anyway.

For the longest time GM used the same 100k NTC thermistor element in every single sensor that measured any kind of temperature - ambient, interior, coolant, intake air, everything. Plastic body IAT or metal body, open element or closed, discrete IAT or integrated into the MAF, all the same electrically. Now, they may have fiddled calibration values here and there to tweak things, but the sensors (the '100k' ones) have the same guts in them.

The later MAFs with the axis that goes from 50 to 43k, I believe those are using a generic '50k' thermistor element. So now there are two...

edit: and... these are likely generic commodity parts, with something like +/-10% tolerance. Swapping one sensor for a different, identical sensor could have more difference between them than what's in two different tune files both using the '100k' thermistors.

[Alvin]

Its important to copy the X and Y from the table. Not all of them are close to the older/newer one. Some calibrations have drastically different axis's.

My point about the 08 G8's.. the IAT reads completely differently as in different thermister *from memory* than the other 2 normal options we have.

[lsagto]

Got the new MAP in, good to go. So the car does have slight rich tip in but more so lean tip out. Transient fueling needs to be adjusted, but my question lies is should I adjust and modify from the GTO table or should I paste in the transient data from a CTS-V and go from there?

[blindsquirrel]

I believe you have rediscovered the reason why some people swear never to mess with rect port blower on cathedral port heads using adapters. The adapters get in the way, with the weird injector location in the LSA port.

[lsagto]

It has ported LS3 heads, no adapters

[cadillactech]

Got the new MAP in, good to go. So the car does have slight rich tip in but more so lean tip out. Transient fueling needs to be adjusted, but my question lies is should I adjust and modify from the GTO table or should I paste in the transient data from a CTS-V and go from there?

How close is your VVE table using a wideband?

[nathanhine1977]

Hi Mate.
I have the Same ECM, E40
Just looking at your tune, I see that your injector tip temp i zeroed out, this will play with fueling in regards to water temp.

Here is my file for a compasrison
1900 Magnuson
LSA injectors.
Approx 10psi
Offsett Data 1st Dec 2022.hpt

[lsagto]

The VE table is about within 5%, so this is the tune I have been using. I turned LTFT in hopes to compensate for the lean tip out and rich tip in but cruising wise its pretty much on the money. This file I do have injector tip temp table being used. Tune #20 CL.hpt

[Lakegoat]

Turn off LTFT's and use STFT's to tune. I turned mine off forever. You can modify a few cells and cure the tip in. If the "tip in" is when you are at idle and it stumbles when you touch the gas, then look at those couple of VE cells and modify them and a couple of others aaround them, then smooth. That should cure the stumble. I'm pretty sure that when you let off the pedal, you will have some lean---since you let off the gas.
Look at your ETC Scalar. That looks way low to me. Can you use the stock 90mm TB ?

[nathanhine1977]

Hi, can you upload a run file, I am interested in you PE Enable tab, it says Min MAP= 13.8psi,
Mine is set to 2.2psiMin MAP PE.png

[blindsquirrel]

Hi, can you upload a run file, I am interested in you PE Enable tab, it says Min MAP= 13.8psi,
Mine is set to 2.2psiMin MAP PE.png

Those numbers are in absolute pressure, as in referenced to a perfect vacuum. Not boost, which is the amount above normal atmosphere. 2.2 PSI absolute is a MAP reading of 15 kPa - so basically, anytime your engine is running it's met the enable target for Min MAP. You're using throttle position only, which is kinda dumb, if that was the way you intended it to work. PE should be load-based, and load is not always related to throttle position. But MAP definitely is related to load.

You should really drop the 'PSI' thing and learn to see it the way the MAP sensor sees it, otherwise you end up making mistakes like that.

Looking at more of your file... what a mess. Dynamic Disable/Reenable is 8,192, but the MAF isn't failed? And MAF codes are set to No MIL?

The 105 kPa columns in both VE tables should be the same.

screenshot.28-07-2023 00.49.19.png

[nathanhine1977]

Thanks for the help.

Alot of the settings are the way I found them.
As to the VE tables I find that the way I drive is that I am either under 105kpa or maxing it out, in the boost table my manifold pressure goes from 105 -> 171 pretty quick.

Please fell free to help me understand some of the things that you have seen that are suspect so I can dial her in better.
Thanks you. here is a log file.17th Dec afteroon log.hpl

[nathanhine1977]

This is a STOCK tune file for the same car, this is where the numbers came from for the PE enable table1443938689.hpt