Greenhorn

[blandmiller]

The VE table is actually indicating the engine's ability to completely fill the combustion chamber with air. It's nature is not to add fuel, it doesn't care about fuel. The VE tables are used to calculate the air/fuel charge.

6 degrees of advance sounds way out there, but I guess it works for you.

I am still confused as to the timing controlling AFR in closed-loop. The PCM already backs timing when it encounters knock while it is still toggling around stoich. KR has no effect on the commanded or actual AFR.

I agree that pulling timing is easier than adding fuel to reduce KR, but 16 degrees seems extreme. Are you seeing 16 degrees of KR? Allow me to quote ds8 from 10-11-06 on another forum, "My knock retard was at 8* at RPMs greater than 1400 all the way to redline with MAP at or above 85 kpa. KR was at least 5* in the same RPM range with MAP at or aove 50 kpa."

How about posting a screenshot of your 'low Rpm non-PE spark advance' table.

I am not trying to be a pain, I just want to try and understand what you are doing.

[ds8]

I never said that commanded AFR changes knock, that is your supposition. AFR of 14.6 tells you that you are not in PE mode and that you should be taking out advance in the non-pe table.

The VE table is actually indicating the engine's ability to completely fill the combustion chamber with air. It's nature is not to add fuel, it doesn't care about fuel. The VE tables are used to calculate the air/fuel charge.

VE is really an arbitrary number since the I6 (pre-maf) doesn't know directly what mass/volume of air is really entering the intake. The air fuel charge is commanded to 14.6, but by chaing VE you can produce different true AFR's because the injectors pwm is determine by looking at a VE table based on load and RPM. Put in a higher VE value and the engine will run rich (on the wideband) even though the commanded AFR is still 14.6.

I agree that pulling timing is easier than adding fuel to reduce KR, but 16 degrees seems extreme. Are you seeing 16 degrees of KR? Allow me to quote ds8 from 10-11-06 on another forum, "My knock retard was at 8* at RPMs greater than 1400 all the way to redline with MAP at or above 85 kpa. KR was at least 5* in the same RPM range with MAP at or aove 50 kpa."

I think the max retard the pcm can command is 8 degrees. I have never seen more than that even though the timing was advanced 16 too far.
I pulled 16 degrees out of the wait4me tune. The most I pulled out of the stock tune was 9 degrees and many of the fields were only 2 to 3, and I added a bit in a few cells. This is why the stock tune is far superior to the wait4me tune.