Help identifying why main spark table is not being used under high load

[EFIExpress]

I've got a 6.0L gen 3 tune I'm working on. I cant figure out why, but at high load it does not seem to be following either the high or low octane main spark tables. I've tried adjusting the min tps and max speed parameters to ensure its using the primary spark tables but nothing in there seems to be working.

I've attached both the config (I've severely retarded the upper portions of the spark maps trying to see if it was using the values at all), and the log. Can anybody shed some light on what I'm doing wrong here?

messed_up_spark_advance_not_retarding_under_boost.hpltesting_escalade_chuck_hubbard_1bar_too_much_advance_pings.hpt

[Russ K]

Your cyl air is higher in the spark histogram then in the table & chart displays. Check to see if you have a custom pid that is affecting the histogram.

Russ Kemp

[jimmyblue]

When I see "1 bar" and "boost" in the same setup I
have to wonder. Like maybe something funny is done
to air mass and your true cylinder air is twice what
you're indexing the spark table by.

[EFIExpress]

Your cyl air is higher in the spark histogram then in the table & chart displays. Check to see if you have a custom pid that is affecting the histogram.

Russ Kemp

I have not modified the spark histogram. I only added a wideband o2 and air temp histogram at item #10 and #11.


also I forgot to mention the vehicle has a 2bar map sensor installed.

It must be something specific to the config on this vehicle, because I did another just like it (slightly different PCM) without having this issue.

[Russ K]

You can't use a 2 bar map with the stock 1 bar os.

Russ Kemp

[EFIExpress]

You can't use a 2 bar map with the stock 1 bar os.

Russ Kemp

I tried using the 2bar supposedly SD tune but it was somehow still using values from the MAF despite failing it correctly in the software, which is why I reverted back to using the 1bar standard OS.

the other truck I tuned also on 1bar OS with 2bar sensor, no problems. there is something specific with this tune/setup that is causing this issue, not just "it wont work".

[EFIExpress]

so, looks like I'm on my own here? I guess I can give it another shot on 2 bar SD, but I've got a decent amount of time into the fueling and idle on the 1bar OS. there has gotta be something simple I'm missing. guess I'll go back over the other truck's config and see whats different.

[blownbluez06]

You're not on your own. If you're in SD mode, not using the MAF, you must delete it from the table. Referencing it in the table will totally screw up your airflow data. Delete the MAF PID. You can only have one MAP and if you have a 2-bar MAP, you have to have a 2-bar MAP pid in the table and no other MAP. If you don't have a 2-bar OS loaded, chances are that you will not be allowed to add the PID to the scan because it scans the vehicle parameters before running the scanner and it must be in the list of scanned items.

[jimmyblue]

So you not only should ignore the MAF, but you must
not even look at it sideways?

[blownbluez06]

So you not only should ignore the MAF, but you must
not even look at it sideways?

I've had problems with skewed airflow values when allowing the MAF to stay in the config file and confirmed when the problem went away after removing the MAF pid. I'm pretty sure I've seen Bill mention this as well. Have you never had the same problem? Might just be certain year PCM's. I mostly deal with 97-04 Vettes.

[Exidous]

Your cyl air is higher in the spark histogram then in the table & chart displays. Check to see if you have a custom pid that is affecting the histogram.

Russ Kemp

Has anyone noticed the spark histograms reading half the air mass the PID table is? Started doing this after 2.24 came out.

[blownbluez06]

Has anyone noticed the spark histograms reading half the air mass the PID table is? Started doing this after 2.24 came out.

I've been seeing it since 2.22 when people mess up the tables in the scanner.