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a91what

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First lets take a look at what I mentioned as "almost hitting targets"
what I look at is the difference between the AFR and the AFR target..
1625670301150.png
Above I have loaded your tune file and your log file into MLVHD, this program is not free but I use it for everything. The Z axis is the recorded AFR and the Z axis delta is the AFR target.. by subtracting the target from the AFR you can see the difference between the two values.
Lets take 95KPA and 4400RPM the value in the cell is 0.53 this means that the AFR is 0.53 points leaner than target. This allows use to quickly glance at the cells and see how far off the tune is, looking at raw cell data like this can be beneficial but its even better if we know how much we need to alter that VE value to achieve target...
1625670598794.png
Now this is not a stock field, I created this under "calculated fields"> custom field> Field = [AFR]/[AFR 1 Target]
this is a simple field that gives us a basic value that we can use to see how much each cell needs to be altered. The same cell we were looking at above needs to be multiplied by 1.04 ( increase of 4%) to reach its AFR target. This field allows us to see how far off the tune is as a percentage and in my opinion is more useful than a raw value.

Lets look at idle for a moment, I noticed that the idle sometimes oscillates before CL idle kicks in lets find out why.
1625671490094.png I grabbed a snip from a point in the log file where the idle is relatively stable, take a moment and look at the fields I have on the 3 graphs. In general idle is controlled by the idle valve and timing.. the idle valve can be considered rpm over time and the amount of timing is immediate change to the idle speed.
Notice how the idle pwm value is very close to the needed value as it returns to idle, then you have an rpm dip and the idle pwm value has to increase to maintain the idle speed... this tells me that the initial values table in the idle settings needs to be increased for this RPM by 3-5% so that the idle comes in just above target and then ramps down to the target idle speed. Notice how much timing the idle advance value has to add to keep the idle from dropping below target speed.
Lets look at a point where the idle is upset.
1625671822185.png Notice how the pwm valve has to open and it adds timing to stop it from dropping below target then the idle swing begins.. this snip shows how the settings are fighting each other to attempt to maintain idle speed. notice how the timing advance [yellow line bottom graph] drops off hard as it enters idle, this is normal when using the idle advance feature but the idle PWM value is not higher to compensate for the abrupt drop.

With these things in mind give the software some attention and focus on these parts. Im out of time today.
 

DemonGT

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First off this is alot of excellent info and should be moved over to your sticky thread "Megasquirt/tuner Studio Tech Thread".

For the Fuel table will a few more autotune drives get this closer or do you recommend manual changes also?

For the idle, if im sorta understanding this is that because the value in the idle initial value table is to low its allowing the rpm to go to low
below the set speed causing the timing to have to advance alot to catch it. The goal is to have the idle pwm catch the rpm before the timing has to advance that much to give it more..."soft" landing at the target idle speed? Would i add some to the whole table or just the 900rpm column 0-212?

Do you recommend megalogviewer MS or HD for the average user? I have the free lite version but being able to do histograms like that would
be really helpful. Also, do you have any experience with TS Ultra? I dont remember even seeing the Ultra one when i bought mine.
 

a91what

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Mlvhd is for more than just megasquirt. Mlvms is for ms specifically. I tune a range of things so I prefer hd

I also use the ultra but it has alot of features that are not necessary for the average user.

You are correct in you above statement, just the hot idle values. I would manually tune the wot fuel and then not use autotune anymore the rest of the tune is very close.

You may want to consider changing the idle advance settings from "use pid" to "use engine state" I find these are simple to setup, they are found under the general settings.
 

DemonGT

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I do not plan on using anything other then MS so i will have to purchase the upgraded MLVMS tonight.

Should i do the MAT/CLT correction you posted in your other thread?

When you get a min i would also be very interested to know more about the EGO stuff as i do not understand any of that.
 

a91what

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I do not plan on using anything other then MS so i will have to purchase the upgraded MLVMS tonight.

Should i do the MAT/CLT correction you posted in your other thread?

When you get a min i would also be very interested to know more about the EGO stuff as i do not understand any of that.
I no longer use the mat\clt correction unless I find that it's needed.
 
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DemonGT

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Looking at the idle advance settings, if i change it to "use engine state" its set default to 120 degrees and 1 for delay. The idle advance timing
is set to 20 in all four boxes shown above load%. Do i need to adjust these boxes?
 

a91what

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Apr 6, 2011
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Looking at the idle advance settings, if i change it to "use engine state" its set default to 120 degrees and 1 for delay. The idle advance timing
is set to 20 in all four boxes shown above load%. Do i need to adjust these boxes?
Do not adjust those boxes, change to 0* and 1s
 
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DemonGT

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May 24, 2002
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Made some changes to Fuel table and the idle pwm. Also changed the idle to "use engine state".

Went on a drive through traffic which wasn't fun but i DID remember to datelog this time. Car seemed to drive ok, it did
have a bit of a surging idle at stop lights. I pulled into the garage and grabbed the laptop to see if i could make some changes
to correct the surge but then it didn't seem to have a surge once i was in the garage. 1773s in the log is where one of the
surging idles starts.
 

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