My commanded AFR is changing rich on me!

[joecar]

DYNCYLAIR_DMA indexes into B5913 and B5914 to see where you are on the spark map.

DYNAIR is calculated from PCM using MAP, RPM, Temp, and can be used to compare VE and MAF.

[Chris81]

Ok cool.. i'll do some logging and post up.

Thanks for the help!

[ScarabEpic22]

Random question, joecar how do you get the scan tool to link up both RPM columns like that?

[joecar]

Random question, joecar how do you get the scan tool to link up both RPM columns like that?

Erik,

In the scantool chart display, drag the vertical cursor to select a portion of the chart trace (i.e. say a few seconds worth, covering a range of RPM say)... then in the tunetool you will see those RPM rows/cols highlighted...

This feature allows you to correlate a very specific part of the chart trace to the tunetool tables cells/rows/cols... very handy as you can see.

Cheers
Joe
:^)

[eficalibrator]

The HOS2x1 voltages 850-905mV indicate a little lean at WOT... 920-930mV would be good (but do use a wideband).

Don't fall into the trap of believing narrowband O2 data at WOT. It's absolutely useless, especially if you don't know the temperature at the tip of the HEGO. You're on the right path when suggesting to just use a good wideband here.

I haven't had a chance to pour through the files, but you may also want to look at the AIR or IVT gains to see if one of those is responsible for your change in commanded EQR. The PCM will always take the richest of its EQR commands in an attempt to remain safe. So, even if PE isn't that rich, something else very well may be...

[joecar]

Greg, very good point... "use a good wideband".

[joecar]

Greg,

Unrelated to this thread, a question that I'm still not sure about:

If running with CLMAF, what happens at WOT... does the PCM still use the MAF or does it revert to VE...?


</hijack>

[ScarabEpic22]

Erik,

In the scantool chart display, drag the vertical cursor to select a portion of the chart trace (i.e. say a few seconds worth, covering a range of RPM say)... then in the tunetool you will see those RPM rows/cols highlighted...

This feature allows you to correlate a very specific part of the chart trace to the tunetool tables cells/rows/cols... very handy as you can see.

Cheers
Joe
:^)

Cool, didnt know that! Learn something new everyday thats for sure.

[Chris81]

Don't fall into the trap of believing narrowband O2 data at WOT. It's absolutely useless, especially if you don't know the temperature at the tip of the HEGO. You're on the right path when suggesting to just use a good wideband here.

I haven't had a chance to pour through the files, but you may also want to look at the AIR or IVT gains to see if one of those is responsible for your change in commanded EQR. The PCM will always take the richest of its EQR commands in an attempt to remain safe. So, even if PE isn't that rich, something else very well may be...

Good deal, I always use a LC1 when tuning.. I just didn't have it in for that outing. My actual typically is a little richer than commanded so I shouldn't be lean.

Joecar, thanks i'll richen up the VE a little in those spots, but doesn't my PE rely solely on info from the MAF at that rpm?

Greg, thanks for the insight. Could you possibly give me the ID tag for those tables?

[joecar]

...

Joecar, thanks i'll richen up the VE a little in those spots, but doesn't my PE rely solely on info from the MAF at that rpm?
...

That's what I used to think, but I'm not sure of that anymore.