Timing higher than commanded 2001 Vette COS5

[02sierra4x4]

Has anyone ran into timing being higher than the high octane table? All of the timing modifiers have been zeroed out EGR, IAT, etc. Put the car on the dyno had it between 26-28* took it to the track and logged it and saw 37-40*!?!?!:doh: Any info would be appreciated!

Thanks

[Supercharged111]

How about the PE timing modifier? That'll add timing at WOT. Probably what's happening.

[02sierra4x4]

Are you talking about the fuel mixture spark correction (B5908)? It is zeroed out

[Supercharged111]

That's the animal. I just reread the initial post though and see it's not a couple degrees. Did you log 3D? Those sound like light load cruise timing values. If they're WOT, something is wrong.

[02sierra4x4]

Not quite sure what you mean by 3D? It is WOT just seems funny how it seems to change, just curious if maybe the COS5 has something to do with it? It is really weird to see it move that much over the high octane table?

[Supercharged111]

Man that's an awful lot of timing. Did you put negative values in the boost retard table?

[joecar]

Post log/tune files.

[joecar]

Other than timing being wrong, does PCM execute everything else ok...?

[02sierra4x4]

Other than timing being wrong, does PCM execute everything else ok...?Thank you all appreciate the posts but we actually just caught it. We had 100% in the octane scaler but was actually out of limits. Saved at 99% and had to resave it back to 100% and was no longer out of limits. Rookie mistake good lessonhttps://uploads.tapatalk-cdn.com/20170810/cb374bef3b31f146f34c9d54d81f23fe.jpg

Sent from my SM-G930V using Tapatalk

[joecar]

So it's good now...?


Note for other people reading this thread:
when you open a tune, go View->Show Calibration Window, and goto the Out of Range tab, if you see any tables mentioned here you should fix each one;
when you go to those tables, you will see the out of range cells marked with either blue dogear corners or with a red box around the cell;
you fix all the OoR cells by doing this:
- edit the OoR cell to either max-1 or min+1,
- do this for all the OoR cells,
- save tune,
- exit tunetool,
- reopen tunetool
- set each of those cells to max or min as appropriate,
- save tune
(this is a special trick required due to tunetool only saves changes it detects, and setting an OoR cell to min/max is not detected).

[Supercharged111]

What other sorts of weird stuff do OOR cells do? Any reason why, when setting to max/min, it shows as OOR thus requiring the fix above?

[joecar]

When the PCM encounters an OOR value, it has to do some extra processing to "fix" it...

this extra processing may be simple or it may be complex (you don't know what it is doing, it may be good or bad);

generally (in software), if you can minimize the execution path, you get better performance and you avoid any problems that the extra processing may introduce

( the most traveled path is the most debugged path )

[joecar]

For OOR cells, the tunetool displays max or min (whichever is closest)... and marks the cell as OOR;

so even tho you see max or min value, if the cell is marked then its real value is beyond the min-max range;

let's say if you see max and it is marked OOR, and you set it to max (i.e. you type in the max value), the tunetool does not save any change to the tunefile, that is why you have to do the special trick.

[02sierra4x4]

So it's good now...?


Note for other people reading this thread:
when you open a tune, go View->Show Calibration Window, and goto the Out of Range tab, if you see any tables mentioned here you should fix each one;
when you go to those tables, you will see the out of range cells marked with either blue dogear corners or with a red box around the cell;
you fix all the OoR cells by doing this:
- edit the OoR cell to either max-1 or min+1,
- do this for all the OoR cells,
- save tune,
- exit tunetool,
- reopen tunetool
- set each of those cells to max or min as appropriate,
- save tune
(this is a special trick required due to tunetool only saves changes it detects, and setting an OoR cell to min/max is not detected).

Yes Sir! Thank you for the info makes since, I believe we changed it but didn't realize it was still OoR.