Learn me fuel only megasquirt tuning

Not being an MS person, perhaps there's an error of what is stoich.  So you can put 14 in the cells.

But while you are driving, does it maintain 14.6 on an a/f meter?  

Are you taking data for others to review?  That would be a really good idea.

I'll have to look up how to take data and share it. And I'm honestly not looking at the gauge while I drive because it's been so long since I've driven that car it really is a handful at this point in time. Feels right to be back behind the wheel but I forgotten what twitches and noises and everything else that car has so I'm focusing on driving instead of the computer.

In reply to Dusterbd13 :

Welp, you screwed the pooch alright.  What you've done is gone ahead and tuned your motor successfully.  Now what the hell are you going to do?  Drive it some more?

You should.  Rinse repeat until you get all of the appropriate cell ranges tuned fairly close (the higher RPM/load ones will be hard to do on the street, which is where dyno/track tuning comes into play).

Eventually you'll notice that acceleration enrichment will need tuning (which is essentially like tuning a acceleration pump) which will really help with drivability.

Once you get the number of changes down to a minimum, you can start data logging and just driving around and reviewing the log files afterward.

https://www.youtube.com/watch?v=LeqAzDNOeaI

Take file and put it on dropbox or similar, submit link here.

View log files on MegaLogViewer, etc.

At what point do i work on ignition curve more? Im pretty sure i have the advance curve wrong, as i set it up from memory when it had a carb and distributor and different intake and trans and......

Thanks for letting me know that I'm approaching this properly. I'll admit coming down my dead end Street by did romp it and 2nd and forgot just what a hoot that car was.

In reply to Dusterbd13 :

Sooner than later.  The old adage goes something like- most carb problems are traced to the distributor.  Just get it close- you can fine tune it later.

Cool. Ill double check it tomorrow against what i think it should need just to make myself feel better, but 38 degrees all in by 3k should be plenty. No vacuum advance on this distributor, so that makes things simpler.

And timing readings dont change with Engine temperature, right? So i can check mechanical asvance on a cold engine. Right?

In reply to Dusterbd13 :

If it changes, something is wrong... ;)

That is what i thought, but its been a minute and ive slept since then. Thanks for confirmation. 

How long should i try to keep in certain areas? Or am i overthinking it?

Datalogging:

Just hit "Data Logging > Start Logging," pick some where to save the file, then drive around.  The datalog lets you look at what the AFRs were after the fact, so you don't have to pay attention to the gauge while driving.

When are we "done":

You're done with a certain area of the map once the measured AFR matches the desired one.  Once most of the map is within +-10-20%, you can probably drive the car mostly normally, while running auto tune, to dial in the last little bit.

Over on the right side under "status" there is a visual representation of what it's been doing during the current tuning session.  The top display shows which cells have seen lots of activity (yellow = some activity, green = more activity).  The bottom shows the amount of change in each cell.  The more blue the cell is, the more fuel has been added in that part of the map.  Red is the same, but for fuel removed.  When the map is getting close, the "Cell Change" section won't have any bright blue or red sections, as only tiny changes will be made.

The "VeAnalyze stats" section also contains some stuff that's useful for deciding upon "done", like the average change its made to each cell, and the largest change in any single cell.  When these are small, you're closer to done.

Also, for reference, here's what my AFR target map looks like. I have a turbo so it goes above 100 kpa, but you get the general idea.  The lean island that extends up to 120kpa in the 2250-3500 range is so that the engine runs a bit more efficiently during highway driving where I at least pretend to care a little more about efficiency.

Dusterbd13 said:

How long should i try to keep in certain areas? Or am i overthinking it?

Based on what I'm reading here, once you get a close cal (which you are right there with), you don't need to worry too much about it.

The only caveat I would have is to tune the transients and not totally rely on the VE tables to get that right (or rely on the WB sensor).  I've got plenty of experience with super well calibrated air calculations, really good WB calibrations, etc, etc etc, and I still need to spend a lot of time getting transient response to work perfectly.  

One of the things about taking data- you can learn more what you are doing, as people here can describe better what is going on.  Over time, you should learn enough that you can fix stuff on your own, too.

Awesome.  Right now it already drives almost as good as it did with a well tuned carb. Definitely have more work in ignition timing, hot restart, and cruise characteristics to go. 

If i get the time/weather to do another run tonight, ill datalog it and try the Dropbox thing during the run. That way yall can help me understand what is happening, and what needs fixed.

You guys have been the most helpful resource BY FAR for me, especially with the difficulty i have in comprehension these days. 

Thank you all.

re. the ignition timing requirements, i don't think they'll change much with EFI vs Carb.   timing requirements (aka what the engine "likes") is more dictated by the fuel you use and the hard parts of the engine, like combustion chamber size and shape, cam profile, and intake and exhaust flow characteristics.  certainly there's some effect due to rich / lean mixture, so my statements above are for apples/apples AFR.

also, berkeley YEAH!   the world needs more rowdy Dusters!!!

Set decel fueling to 100% before you do any auto-tuning. If it turns off fueling on decel, the auto-tune will increase the VE numbers to try and get that fueling back.
I don't know what you're using to tune, but in TunerStudio, decel fueling is in the accel enrichment section.

Get your idle set, and then change the autotune RPM to only work above ~1000 or so. Don't let it continue to tune idle. ONLY TUNE IDLE FUELING WHEN ENGINE IS FULLY WARM. From there, you'll use warmup encrich to change fueling based on temperature.

Also, I assume your megasquirt isn't doing a full 8 cylinder sequential injection, its doing batch fire. If thats the case, change your Target AFR table so that it wants ~13.7-14 AFR in idle and cruise areas instead of 14.7 AFR. It will run much more steadily while being batch fired.

Start out with the 'Very Easy' setting on autotune while cruising around. It'll take fewer hits in each cell to change the amount, so you won't have to hold it steady while driving. Also, if the 'Update ECU' box is checked, you don't need to flash the computer at every stop, its updating for you. You will have to flash it when you're done. After a nice long drive on Very Easy, switch it over to Easy and start over. Then repeat on Normal. It'll highlight the cells it has changed in Red/Blue. Blue adding fuel, red reducing fuel. Try to go through and manually change all of the other cells that didn't get hit so that they more smoothly transition through the table. You can check the 3D view button from time to time to see where the really bad high/low points are. Once the table is fairly steady, highlight the entire VE table and click the smooth button. Then you get autotune on the Hard or Very Hard settings, and once again move around any unchanged cells before smoothing the entire table. Should take one afternoon or evening, and you can pretty much get fueling on the money.

Ill have to look when i get home, but dont recall seeing the very easy-very hard settings. Im using the paid version of tunerstudio. 

Thanks for the tips. Again, need to look at the program when i get home, as i dont think i have the options youre talking about (however, after 12 concussions my memory ain't what it used to be)

Dusterbd13 said:

Ill have to look when i get home, but dont recall seeing the very easy-very hard settings. Im using the paid version of tunerstudio. 

Thanks for the tips. Again, need to look at the program when i get home, as i dont think i have the options youre talking about (however, after 12 concussions my memory ain't what it used to be)

I'm using the paid version as well. The Very Easy - Very Hard settings is a drop-down box above the settings for minimum RPM, coolant temp, etc in the autotune section. Using the Very Easy settings allows the cells to be changed almost instantly on the fly, which helps with cells that you'll spend a very short amount of time in that wouldn't get enough hits on the Normal setting. You'll want decel fueling at 100% to prevent multiple fueling conditions within a given cell while autotune is on. Go to the accel enrich section, its on the right somewhere on the page where you choose MAP or TPS enrich settings.

found everything you were talking abput except the decel fuel. not finding it at all. 

i also got the ignition curve dialed in a whole lot better. especially seein that i didnt tighted the distributor, and it all changed on my autotune session. now if it would stop raining, i could go do more.....

I'm at work, so this might not be 100% accurate.

Look for decel fueling in the accel enrichment tab. It'll either be Accel Enrichment Wizard or Time Based Acceleration Enrichment.
Set it to 100% while using autotune.

In reply to Dusterbd13 :

https://www.diyautotune.com/support/tech/other/accel-enrichment/

ok. the article reccomends 90-95 as the setting. is this correct for autotune? or should i go to 0 as suggested earier to eliminate it entirely so it doesnt mess with the tables?

If you're using autotune, you set it to 100 (meaning no change to decel fuel from the map's normal value).

ok. wanted to make sure im doing it right. hopefully rain holds off long enough tonight to go for a tuning run.