Sparks Higher than we are asking

[Forcefedperformance]

We Have A 00 Corvette that has more spark on the data log then what is in the file and cant seem to figure out where its coming from..... Anyone care to take a peek and see if you can find out where is coming from??

Bill

[WeathermanShawn]

Hi ForcefedPerformance:

I'll take a shot at this. The only thing I can remotely see is the negative integer in Table B6205. I wonder if that 'adds' to spark. Normally positive integers take spark away..so perhaps negative adds?

Just a thought. It would be 4 degrees. Got to say I have never seen this before...

[TFZ_Z06]

We Have A 00 Corvette that has more spark on the data log then what is in the file and cant seem to figure out where its coming from..... Anyone care to take a peek and see if you can find out where is coming from??

Bill

try logging DYNCYLAIR_DMA vs DYNCYLAIR. To the best of my knowledge
the DMA PID is the one (listed in the tune tool for high/low octane spark tables) and the one used by the PCM. Yes, I know the tune tools says you can use DYNCYLAIR, but maybe thats because the units are the same and the data is practically the same. As you have proven though, it is slightly different and based on your log looks as if the PCM is using DMA for lookup.

It is my opinion that the PREDICTED airflow is just that. Perhaps related to transitional throttle conditions for MAF cross checks? IE, is predicted ~= to the MAF data? But is not the ~actual and current data. It is also my opinion that the DYNCYLAIR_DMA is end adjusted, perhaps by ECT/ACT or other values. It would be nice to see an actual disassembly of a file to prove this out.

Not to confuse the matter more, but all PIDS are DMA. I think DMA might be a term loosely termed by EFI to describe calculated/predicdted vs actual data.

BTW, I already know Keith has about as much use for MAFs as Texas does for liberals.

[joecar]

Plain pids:
- scantool can request PCM to tell it which pids it provides/supports;
- scantool can request PCM to return value of a specific pid (by name).

DMA pids:
- scantool requests PCM to return value of some internal memory location;
- that memory location would be some internal value that the PCM uses/computes;
- PCM does not report DMA pids (i.e. the scantool already knows about DMA pids).

Calc pids:
- user defines these in calc_pids.txt by writing a mathematical expression;
- can be applied/saved after a log has been captured;
- has dependecies on other pids (plain, DMA, calc).


Keith who...?

What's a MAF...?

I do know about the nation of Texas.

I see liberals all around me driving Toyota Pious's.

[joecar]

Bill,

I looked all thru your tables and I couldn't see where from...

Try logging the EST_ (electronic spark timing) _DMA pids, maybe one of those will reveal the source of that timing.

[TFZ_Z06]

Keith and Bill are two exceptional LSX guys at that shop that I happen to know.

Incidently, I spent a few years in Texas so have some knowledge of the place myself. Great people. Based on how things are progressing here, I may have another opportunity to visit the TX nation.

I don't really have a problem with Prius driving liberals (ok maybe w/their thought processes... ) , but what really stinks is when they get self righteous about you driving what they want you to drive. This state will self-destruct w/that thinking.

In any case, do you know what the tech difference is between
DYNCYLAIR and DYNCYLAIR_DMA?

[WeathermanShawn]

I will stick with this theory..

They are in PE Mode and experiencing KR. Because B6205 was inadvertently entered with -4 KR..If in power enrichment mode, then knock can only retard the timing by these values..the KR is actually being added..(- (-4)= +4..)

They can not see it being added, because the chart properties of KR do not show KR being added, only subtracted..(max 0.0)..

I know it sounds bizarre, but is it possible they are experiencing KR and the spark is actually being added???

[joecar]

Shawn has a good probable analysis... the experiment to do is to zero B6205 and see what timing is observed.

[joecar]

My understanding:

GM.DYNCYLAIR:
PCM calculated cylinder airmass [g/cyl] based on VE.

GM.DYNCYLAIR_DMA:
Internal PCM calculated cylinder airmass [g/cyl] based on VE.


Most times those two agree with each other, but sometimes they are different.


The non-DMA pid is available to all 'enhanced' scantools...

The DMA pid is the EFILive scantool lookup of internal memory in the PCM, this value may be before and/or regardless of the value the PCM places in the non-DMA pid... i.e. special privy into the PCM's internal calculation.

[joecar]

<hijack, sorry>

Yes, I don't care that liberals drive Pious's (can you tell I don't like that car )...

Like you said, I don't like that they dictate what you shall drive...

see this: http://www.youtube.com/watch?v=rAqPMJFaEdY

(you'll be allowed to drive your Pelossi GT SS R/T man-car on designated driving days... sounds humorous, but it is heading in that direction).

Also, hyper-milers cause moving bottlenecks on I-405 each morning... ridiculous and unsafe practice...

</hijack>