$42 Tuning Questions??

[devind]

I am very new to the tuning game and I have been in the process of tuning my Jeep with a 355 Chevy with Vortec heads and mild comp cam
http://www.compcams.com/Company/CC/c...x?csid=98&sb=2.
Here’s a link to my original post when I first came on board it has more details on the actual build of my Jeep and it’s motor
http://www.gearhead-efi.com/Fuel-Inj...-proram-issues

I had Dave w of Old School EFI tune a chip for me after having issues with TBIchips.com.
Dave has done an outstanding job getting all of the issues I was having fixed and has the Jeep running very well now.

However during this 7 month process I have learned a lot with a BIG thanks to Dave W and this forum.

I just recently bought a burn 2 from Moates so that I could burn my own chips if I needed to make small changes. Plus it just made sense to be able to burn my own chip rather than mailing them back and forth. Not to mention I believe I have caught the tuning bug and plan to continue to learn and try to increase my knowledge for future projects. I am now thinking about buying the Auto prom and selling the Burn 2.


Back on subject and my main question today has to do with the setting of the distributor’s base timing.

On my current tune I have to distributor set between 9 and 10 degrees BTDC (With anything less than 7 degrees the motor just falls on its face under acceleration).
With the base timing in the bin set at 0 and the spark bias set at 9.84.
Also I have double checked the balancer to make sure that it has not spun. The mark is reading perfectly on 0 at TDC. In addition I have added a knock sensor to the system that I originally didn't have.

I have spent some time with the timing light and have compared the timing at various rpm levels against what I am reading off of the crank and what Tuner Pro is reading. I even tried to manipulate the map reading with a hand held vacuum pump while trying to read the timing. But I didn’t have much luck because as soon as I would release the vacuum to the map sensor the motor would flood due to ecm seeing a load and start adding fuel.

But consistently the crank readings are what Tuner Pro reads plus the 9.5 degrees set at the distributor.

I have also compared the spark advance history table to what is programed in to the main SA table and they are consistent minus the 9.84 degrees of spark bias.

With all this said it runs great and there are not any issues. Like I said earlier Dave w has done a great job tuning it for me.

I have come to the understanding with tuning like most things in life there are more than one way to skin a cat. Therefore tuners have different methods of tuning to reach the same goal of a properly tuned motor.

But with me trying to learn how to tune and understand the process I get confused when I read threads where Eagle Mark is very adamant about not running any advance timing with the distributor due to it throwing the injector timing off with the spark timing.

I want to make it perfectly clear, I am not trying to throw anyone under the bus or call anyone out on whose tuning method is better than the others.
I am just trying to better understand it all and hopefully in the end see what the pros and cons are to the different methods.

[EagleMark]

The reason I am adamant about leaving things alone and working with spark table is because so much can go wrong! Very rarely do you need to change anything but Spark Advance table.

Like which XDF? Does it show actual spark? Or spark with bias? Or is bias removed in conversion? Or is bias removed with link to bias? My new XDF is linked to remove bias from bias setting so you are always looking at actual spark, if you change bias and re open spark advance table it has changed! This way it always works, SBC has 9.84 bias, BBC has 0 bias...

But consistently the crank readings are what Tuner Pro reads plus the 9.5 degrees set at the distributor.

Good! If your bias is factored in. Bad if not!

I have also compared the spark advance history table to what is programmed in to the main SA table and they are consistent minus the 9.84 degrees of spark bias.

Did you change the conversion in Spark Advance Value of ADX file? It is set to 0, if distributor base setting is changed the conversion has to change
from "(X * 0.3515625) + 0.000000"
to "(X * 0.3515625) + 10.000000"

Without the 10 in conversion to add the 10 at distributor? The history table is off by 10!

See where confusion sets in?

[devind]

Like which XDF?

I am using your $42 - 1227747-V5.1

Did you change the conversion in Spark Advance Value of ADX file? It is set to 0, if distributor base setting is changed the conversion has to change
from "(X * 0.3515625) + 0.000000"
to "(X * 0.3515625) + 10.000000"

Without the 10 in conversion to add the 10 at distributor? The history table is off by 10!

See where confusion sets in?

No I did not make changes to the ADX. However I did realize that values in the history table would be off by 10 degrees.

[EagleMark]

I am using your $42 - 1227747-V5.1

With that XDF file the entire Spark Advance table is 10 degrees (9.84) higher then actual.

You've already caught the ADX is off by 10.

Glad to see you getting involved in tuning after all you've been through!

The only thing about this conversation that surprises me is you still need more timing then Dave has done? Don't worry about Dave and I, we are on the same team and work well together, I doubt this is to do with his tune... just surprised you can get away with more timing then he already does?

How is knock counts? Remember they accumulate so you need to see them rise in data frame by frame in this ECM.

Attached is the newer XDF which will show actual spark advance in table = bias accounted for. Base distributor setting is not!

Also an ADX file with 10 degrees added for actual spark advance. Not including Base setting of distributor!

[devind]

With that XDF file the entire Spark Advance table is 10 degrees (9.84) higher then actual.

You've already caught the ADX is off by 10.

After you posted the formula I actually made the change to the XDF adding the + 10

Glad to see you getting involved in tuning after all you've been through!

Thanks, I have always wanted to but never really thought I would be able to understand it. But between this site and going thru the process with Dave it has started to click.

The only thing about this conversation that surprises me is you still need more timing then Dave has done? Don't worry about Dave and I, we are on the same team and work well together, I doubt this is to do with his tune... just surprised you can get away with more timing then he already does?

How is knock counts? Remember they accumulate so you need to see them rise in data frame by frame in this ECM.

Me too I still don't understand why the motor needs so much timing in it. Dave told me he did one similar to mine for another guy and he had to add 12 degrees of base timing with distributor. There have been very little knock counts and they have only occurred when I get on it real hard doing kind of a drag race start and even then it only shows 1 to 3. However right now I have knock sensor mounted with a brass fitting. Dave suggested I remove the brass fitting and see what it does. However I haven't had a chance to do it yet.

Attached is the newer XDF which will show actual spark advance in table = bias accounted for. Base distributor setting is not!

Also an ADX file with 10 degrees added for actual spark advance. Not including Base setting of distributor!

Thanks for the new files. I will try them out.

Sometime I want to figure out how to adjust the XDF so that the injector duty reads correctly. Right now it shows real low percentages.
But I got to go right now, taking the wife out for our 26th anniversary.

[EagleMark]

Congratulations! I did my 27th anniversary in January.

The injector duty cycle is fixed in this ADX, the XDF hack/patch has always been correct.

Me too I still don't understand why the motor needs so much timing in it. Dave told me he did one similar to mine for another guy and he had to add 12 degrees of base timing with distributor.

Hmmmm...??? Man that's a lot of timing? I can see needed much more at idle if cam is causing a low vacuum...

[devind]

Congratulations! I did my 27th anniversary in January.

Thank You! I am very blessed to have such a great wife. And congrats on your 27th.

The injector duty cycle is fixed in this ADX, the XDF hack/patch has always been correct.

Got it, so the issue was in the ADX not he XDF. I'm still learning, not for sure I total understand the difference in the 2 yet. I know one is a mask to convert the hex to something I can understand.

Hmmmm...??? Man that's a lot of timing? I can see needed much more at idle if cam is causing a low vacuum...

I agree with your Hmmmm...???

Even though it is running really good now I cant help but wounder why it needs that much timing. I even second guessed the the way I checked the mark on the balancer when I built the motor. So I went back and double checked it again using a piston stop. By rotating the motor one direction until it hit then reversed rotated it until it hit and the 0 fell in the center of the readings. I keep thinking there is something I am missing or not understanding yet.

The cam has good idle characteristics the power range is 1000 to 5000 rpm and it maintains good steady vacuum at idle.

[EagleMark]

The XDF is the bin definition mask. A mask is like a map that picks the hex code in bin and translates it to a human interpated value with name we can adjust.

The ADX is a data acqusition file, also like a mask that uses data signals sent from ECM to ALDL port and you can read them.

The problem with injector duty cycle was the amount a injector firings per cycle = 2 which is perfect for MPFI but not 4 needed for TBI = IDC% conversion was half!

[EagleMark]

What distributor and EST module is in the engine?

Here's a way to check the timing at all RPM and remove the MAP axis. Click the top left box of Spark Advance timing table to highlight all, Function, choose Fill with Value and type in 20.00, Execute. Now your entire timing table is 20.00 at all RPM and all MAP readings. Makes it easier to see what EST module is doing at all RPMs.

Now when you check timing marks with timing light it should always read 20.00 + whatever distributor is set to.

[devind]

What distributor and EST module is in the engine?

It is brand new stock replacement, but it is one of those made in china replacements (name on box was World Power Systems)

Here's a way to check the timing at all RPM and remove the MAP axis. Click the top left box of Spark Advance timing table to highlight all, Function, choose Fill with Value and type in 20.00, Execute. Now your entire timing table is 20.00 at all RPM and all MAP readings. Makes it easier to see what EST module is doing at all RPMs.

Now when you check timing marks with timing light it should always read 20.00 + whatever distributor is set to.

Okay when I get a chance I will give that try

[ony]

I like them new adx-xdl file, patch apply works good

[EagleMark]

It is brand new stock replacement, but it is one of those made in china replacements (name on box was World Power Systems)

That sounds familiar as one my kid came home with from O'Reillys, not only was it 6 degrees off at most RPM it did weird stuff whenever it wanted? Stuck an old GM EST in and all was fine.

Just between 2 known GM modules there is 3 degrees taken out about 3000 RPM and 3 degrees added at 3000 RPM (or something like that), Small cap EFI and Large coil in cap EFI have 2 differant latency settings good for 3-4 degrees. Other aftermarket have been off by 2-11 degrees at who knows what RPM. Seems they work but Spark Latency is no where near what GM had originally programmed. I haven't used anything but AC/Delco EST because of this in a long time.

Do the test with engine warmed up to exclude any CTS spark correction. There are other spark adders and subtractors but none you should really hit in parked test.

I'd really like to see the datalog with timing locked to 20! Rev engine to whatever RPM you feel comfortable with, hold a few spots as steady as you can like idle, 1500, 2500, 3500, 4500...

Looking forward to your results!

[EagleMark]

I like them new adx-xdl file, patch apply works good

Pretty cool feature that came out in TunerPRo. Makes things easy!

[ony]

one click

[EagleMark]

Well it's a lot more clicks to set one up! Sure simplifies the end result.