Spark woes

[Phil_f]

2001 Camaro on the dyno, can't get spark to do what I need. while logging RUN_DMA is at 34* , SPARKADV is at 18.5* only way I seem to be able to add timing is by putting a value in the eq ratio table.

[WeathermanShawn]

Phil, welcome to the forum:

First off, you have way too many Pids/Channels being logged. That will cause a major lag in logging data. You need to keep the channel count to 24 or less for valid data.

Second, I am not sure what you are referring to when you are referencing the EQ Ratio table. What are you saying here?

Lastly, if you could post your Tune it will be a lot easier to deduce where your Spark values are coming from. Again, it could just be the 50 channels being logged that is causing the problem.

[Phil_f]

trying to figure out where my spark was going, don't usually log that many channels. tune might be a little hack in the spark and knock areas, try anything at this point.


eq ratio table for spark, 'Fuel Mixture Spark Correction' under 'Spark' and 'General'

[WeathermanShawn]

Well, the channel count may be throwing off the data somewhat. If I look at frame 12..your Spark Advance is 19.0 degrees..you are getting 6.0 degrees of retard from your Trans Torque Reduction Spark. You are commanding 27.0 degrees in your High-Octane Spark table. 27.0 - 6.0 = 21. On Frame 11 2.2 degrees was being deducted from the ECT Spark Table.

So everything adds up..it is just a case of your Frame #'s are not lining up perfectly (50 channel count). Same issue with your Base DMA Spark. It is off by a couple of frames.

As an F.Y.I., there are some cases where putting Spark into the Fuel Mixture Spark Correction is warranted, but I would try reducing your channel count first. You don't seem to be encountering any mechanical KR..I think your Scan & frames are lagging..

Edit..Look at your Cylinder Air at Frame 12..it reads .98..so that correlates to 19 degrees of Spark on your High-octane Table. That data is correct, your Spark values are lagging..

[Phil_f]

Ill give that a shot, why would tranny be pulling spark when I have torque reduction off?

[Taz]

Your transmission torque reduction is still active in D0801 and D0802. If you were referring to D0301 being set to "Disabled" - that does not disable upshift / downshift torque reduction.


Regards,
Taz

[Phil_f]

that doesn't just apply to upshifts? or rather it will pull timing during a WOT run?

[Phil_f]

New run, less channels (i see what you mean by lagging) I zeroed torque reduction for upshifts. Still getting -6.0 deg pulled from tranny?

[WeathermanShawn]

Phil:

I am not an expert when it comes to the Tranny Torque Reduction. Experts like TAZ have far more experience in knowing if and when it is disabled.

However, sometimes the Scan Tool is utilizing a Look-Up Spark Table Value and will display it as a reduction (unless it is zeroed). I assume this PID may also be utilizing a Traction Control feature?

Regardless, here is what may be happening. Even though Table B5913 says it is linked via DYNAIR, you are still MAF-Enabled. Therefore it is pulling your Spark via CYLAIR.DMA not DYNAIR.DMA. If you look at your first log when you logged CYLAIR you were hitting a max of .98 g/cyl. When you switched to DYNAIR you were hitting only a max of .80, but no doubt your Spark Value when properly matched to CYLAIR would have matched up to your WOT Spark Value of 19 degrees.

So, I really don't think it is pulling 6 degrees of Spark via Torque reduction. If you have the time and energy re-log using CYLAIR.DMA. That should match up perfectly to your High-Octane Spark Table.

Good luck..

[Phil_f]

trying that now.

p.s. Can I raise the airflow limits or change normalizers?

[Phil_f]

that seems to be the case, it all jives now. is there anyway to change the tag on the graph?

[joecar]

Hi Phil,

Which pid (tag) and which table (graph)...?

Have you first hovered the cursor over the axis of the table to see if alternate pids are already linked to it...?

Look at the file C:\Program Files\EFILive\V7.5\Configuration\cal_link.txt

[WeathermanShawn]

Phil & Joe:

What is 'odd' about the Scan Tool link to Pid for High-octane Spark, is that it appears to always 'default' to DYNCYLAIR. What I have observed in logging is that when you are MAF-Enabled, Spark will always follow CYLAIR.

However, when you log both DYNCYLAIR and CYLAIR , the link to Scan Tool will 'default' to DYNCYLAIR. This will result in an inaccurate Spark Link to Pid.

Phil, I had forgotten this as I normally only log CYLAIR. That and my DYNCLAIR and CYLAIR are virtually identical.

Joe, I would not really classify it as a software 'bug', just something to remember.

Phil, does that address your concerns?

[Phil_f]

just did that, yes there are three other pids linked to it. i'm looking into the config file now. found this;

;High-Octane Spark Table
B5101.ROW=SAE.RPM
B5101.COL=GM.APCYL_E40_DMA

can i make gm.apcyl_e40_dma = cylair_dma? not sure if there is a pid association lookup or something.

[joecar]

Phil & Joe:

What is 'odd' about the Scan Tool link to Pid for High-octane Spark, is that it appears to always 'default' to DYNCYLAIR. What I have observed in logging is that when you are MAF-Enabled, Spark will always follow CYLAIR.

However, when you log both DYNCYLAIR and CYLAIR , the link to Scan Tool will 'default' to DYNCYLAIR. This will result in an inaccurate Spark Link to Pid.

Phil, I had forgotten this as I normally only log CYLAIR. That and my DYNCLAIR and CYLAIR are virtually identical.

Joe, I would not really classify it as a software 'bug', just something to remember.

Phil, does that address your concerns?Shawn,

Try this: in the cal_link.txt file, locate the spark table id, and change the order of the linking pids.

[WeathermanShawn]

Wow!

You learn something new each day! I got it changed in the cal_lnk.txt you referenced. I'll try it out on my next log, but it makes perfect sense. I simply was not aware of that 'trick'.
Thanks Joe..:cheers:

[Phil_f]

Thank you guys very much for the help, I was going crazy trying to figure out why my spark wasn't working out correctly.

a couple of quick questions while we are on the subject. why would dyncylair_dma and cylair_dma differ? they both measure grams/cyl, which I assume is taken from the mass air flow.
is their something in my tune that doesn't agree?

thank you again for the help

[WeathermanShawn]

Phil:

You are more than welcome. I also learned something of value so it was a 'win-win'.

On the DYNAIR vs CYLAIR. In your Tune Table B5001 MAF Calibration Table has definitely been altered. In fact your MAF Airflow at 10,000 Hz exceeds my H/C car by over 150 g/s. What are your mods? I also see you have some pretty big injectors. What is the engine size?

The DYNAIR is computed from the values in Table B0101 VE Table. Joecar can tell you a lot more about the equation and its derivation. In your case, the actual Airflow Values in your VE Table are pretty low, especially in comparison to your MAF Airflow.

Joecar and myself along with others helped write the CALC.VE Table Tutorial (see my signature for link). In it you can simply compute the VE Table using the MAF Airflow. You do want it close, or when you punch the throttle you will get erratic fueling and possible lean/rich spikes.

Thats the 'cliff note' version..:)

[WeathermanShawn]

Phil:

Also noticed you are running open loop, but your B0120 is set to 3000 Rpm's.

You might want to log a wideband AFR/EQ if you get another dyno run. An open-loop Tune with both MAF and VE Table 'Enabled' is tough to do.

Just to clarify..Is this a Custom OS or a 'regular' OS?

Thanks..

[joecar]

More info, see post #2: showthread.php?14188-Summary-Notes (http://forum.efilive.com/showthread.php?14188-Summary-Notes)

[Phil_f]

the engine is a 383ci with a 150 shot of nitrous, big heads, fast toys maf, fast intake, twin bosch pumps, 80lbs fms injectors, big throttle plate. the ve table i thought was irrelevant after 3k anyway? stock os. logging afr with dyno wideband. have to setup the handheld with an ext. wideband, next time around.

[WeathermanShawn]

Phil:

Granted if you never do any driving below 3000 Rpms, it may not be that big of an issue.

Another reason to map the VE Table accurately is in the event of MAF Failure. It happens more frequently than people imagine. If you are 2/3's of the way down the drag-strip and one those little MAF 'wires' break, your PCM will utilize the Airflow and resultant Injector flow directly from the VE Table. And if the VE Table is under-reporting, you will go lean. But,that might be overkill for some people.

For a street-driven vehicle, driving would be tough open-loop with both the MAF and VE Table 'enabled'.

If you ever have any interest in it, their are certainly enough Tutorials to assist. But, in any case it looks like you have solved your Spark issue.

Good luck..