Tuning 101A, Final Answer
02-04-2003, 08:57 AM
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Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Tuning 101A, Final Answer
How I missed this, I dunno.
When your starting with a new calibration.
Get a commented hac.
Then write down all the tables pertenate to various conditions.
Say for Cranking fuel, then Cold run AFR, the run AFR.
Then your IAC stuff for max IAC park, and your rpm in gear tables, and your warm park posistions.
AE same thing
PE same thing
Timing same thing
Once you get all your conditions and tables all laid out and organized you can glance thru each area to see what is at play, and what to change rather then reading thru the whole hac.
Then if you go another step further and print out the various tables you can overlay some of them and see what's going on in the general picture rather then in just one element.
And you also, ALWAYS, begin with the basics.
Set your timing, inj constant to what they actually are, and build from there. Starting in the middle and working back and forth wastes ALOT of time.
HTH
When your starting with a new calibration.
Get a commented hac.
Then write down all the tables pertenate to various conditions.
Say for Cranking fuel, then Cold run AFR, the run AFR.
Then your IAC stuff for max IAC park, and your rpm in gear tables, and your warm park posistions.
AE same thing
PE same thing
Timing same thing
Once you get all your conditions and tables all laid out and organized you can glance thru each area to see what is at play, and what to change rather then reading thru the whole hac.
Then if you go another step further and print out the various tables you can overlay some of them and see what's going on in the general picture rather then in just one element.
And you also, ALWAYS, begin with the basics.
Set your timing, inj constant to what they actually are, and build from there. Starting in the middle and working back and forth wastes ALOT of time.
HTH
02-17-2003, 11:23 AM
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Agreed.
What I like to do is turn off everything that can influence my readings.
Set the spark tables first. Make sure there are no advance changes where the motor idles. It can cause Idle hunting.
When tuning the VE tables, I turn off the EGR, Canister purge, AIR system , disable PE mode and set the learing to 2 BLM cells.
1 for idle and 1 for everything else.
You can tune an N/A motor by loading it at various points in the table for brief periods.
Log your data and make your corrections.
Next do the PI code.
For tuning the PI code, disable the closed loop IAC operations.
Your proportional gains are to be based off the injector size.
(% fuel per BPW count)
GM adds or subtracts the proportional code directly to the BPW.
Treat the numbers as a percent of fuel change to your current BPW.
At idle the BPW is smaller. So adding 10 counts to it is a huge increase/decrease in fuel. At a higher BPW (cruise) the same 10 counts become less of an influence. It does not take much % fuel change to get the O2 switching properly.
After cleaning up the PI code you will usually find you don't need to mess with the IAC calibrations.
The only exception to this is very low manifold vac. You then need to adjust the IAC PI code to follow the new airflow numbers.
Remember, the ECM does EVERYTHING around it's calculated airflow.
Repeat the above steps to set your base. The go tune the PE.
If everything looks good, turn all of the learning back on. If it still looks good and drives good, you can now go set your EGR offsets, CCP, AIR, etc.
Keeping the smog equipment in working order does not affect performance. I does however make the motor run cleaner which will save gas and make it last longer.
You always need to keep a copy of the Eeprom bin with the logged data file for each test. I like to make folders by date and time to store each .bin and data log.
Make plenty of notes on what you changed. You will be glad you did if you have to go back and change something. If you make a change in the tuning, you have to verify that 1: that's what needed to be changed, 2: the change worked.
As Grumpy said, you need to know what all of the tables do before you make changes. Guessing will just get you lost faster!
What I like to do is turn off everything that can influence my readings.
Set the spark tables first. Make sure there are no advance changes where the motor idles. It can cause Idle hunting.
When tuning the VE tables, I turn off the EGR, Canister purge, AIR system , disable PE mode and set the learing to 2 BLM cells.
1 for idle and 1 for everything else.
You can tune an N/A motor by loading it at various points in the table for brief periods.
Log your data and make your corrections.
Next do the PI code.
For tuning the PI code, disable the closed loop IAC operations.
Your proportional gains are to be based off the injector size.
(% fuel per BPW count)
GM adds or subtracts the proportional code directly to the BPW.
Treat the numbers as a percent of fuel change to your current BPW.
At idle the BPW is smaller. So adding 10 counts to it is a huge increase/decrease in fuel. At a higher BPW (cruise) the same 10 counts become less of an influence. It does not take much % fuel change to get the O2 switching properly.
After cleaning up the PI code you will usually find you don't need to mess with the IAC calibrations.
The only exception to this is very low manifold vac. You then need to adjust the IAC PI code to follow the new airflow numbers.
Remember, the ECM does EVERYTHING around it's calculated airflow.
Repeat the above steps to set your base. The go tune the PE.
If everything looks good, turn all of the learning back on. If it still looks good and drives good, you can now go set your EGR offsets, CCP, AIR, etc.
Keeping the smog equipment in working order does not affect performance. I does however make the motor run cleaner which will save gas and make it last longer.
You always need to keep a copy of the Eeprom bin with the logged data file for each test. I like to make folders by date and time to store each .bin and data log.
Make plenty of notes on what you changed. You will be glad you did if you have to go back and change something. If you make a change in the tuning, you have to verify that 1: that's what needed to be changed, 2: the change worked.
As Grumpy said, you need to know what all of the tables do before you make changes. Guessing will just get you lost faster!
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