Timing will not follow main spark tables.

I'm having an issue with the timing it does not follow the main spark tables. I have zeroed out the IAT, AFR and ECT spark correction tables. It seems that something is retarding the timing and reducing it by approximately 6 to 7 degrees in all areas except the idle. I also zeroed out the burst knock retard tables thinking that may be reducing it Can someone look at my tune and see if they see what may be causing this? This is a 2001 Yukon XL with a 6.0 and lysholm 2300 Supercharger running a 2 bar OS SD tune no MAF. Thanks for looking at it and any help you can give me.

Have you tried logging anything to do with Retarding the timing and check to see where it is being commanded from? That's where I would start.

Remove the MAF from the log...it's messing up the scanner so you're not where you think you are in the spark tables.

For example, at frame 231, you're at 2400 RPM, and the scanner is showing you're at 0.28 g/cyl on the spark table, and you've got 0 degrees of knock and 34 degrees of advance. If you notice, the cylinder airmass is showing correct at 0.59 g/cyl...the MAF sensor is showing 0 because it's not present, and that is dividing the airmass the scantool understands by half...so if you look at your main spark table...you think you're at 0.28g/cyl, which should be 46.8 degrees of timing in your tune, but if you look where the airflow really is (the 0.56-0.60 g/cyl cells), the tune has 34.5 and 34.3 degrees of advance...exactly what you're seeing at the engine.

So open your scanner, with no log, and then open the table display, then right click on "Mass Air Flow (SAE)" and pick delete, then right click "Mass Air Flow" and press delete. Now save your config, and try logging again...you should see the scanner go twice as far down from the top on the spark tables (twice as much airflow)...and the numbers will match up to your tune.

MikeOD thank you that fixed the issue thanks I learned something new and appreciate the help. Now read 40's on the PID where it didn't before. How do I remove the MAF from the tune or is it necessary as I have it failing at 0 and reporting on first error. It is no longer in the intake system at all. Thanks again.

That's as removed from the tune as you're going to get.

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Originally Posted by MikeOD

That's as removed from the tune as you're going to get.

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:cool: