Theoretically, if I were to tune a '94-'95 LT1 ECM / PCM from start to finish, would this be the correct order and method(s) to do so?
Engine would be a: 1994-1995 350ci LT1 with stock bore and stroke. Stock injectors. Stock bottom end, roller lifters, OEM cylinder heads with oem valve size, full roller rocker arms (1.6 ratio), aftermarket valve springs, crane camshaft (.479 / .518 lift 272 / 286 duration, 112 Lobe Separation Angle), headers, OEM narrow band O2 sensor, dual straight pipes, etc.
Very first, make sure all ignition system components, fuel pump, fuel filter, sensors, etc are all in good condition and car is running as good as possible.
Next check for error / check engine codes, if there are any fix them.
Now get vehicle to idle (advance idle timing 2 to 5 degrees, increase idle speeds by 100 to 150 RPM, increase Idle Air Control deadband by 75-100 RPM.) Next go to switches and uncheck anything I deleted such as (EGR, VATS, etc, etc).
Now disable power enrichment & highway lean cruise mode. Then hook my ALDL cable to my OBD port, then ALDL to my laptop. Next open EEhack or TunerPro & then datalog using as many ranges of the accelerator as smoothly and steadily as possible (5% throttle, 10%, 15%, etc all the way up to wide open throttle.)
Drive home, click save datalog and stop logging, turn car off.
Upload datalog to Tunerpro (this is where I will add the actual changes to timing , fuel, etc, etc)
In another window, open EEhack to download and analyze the data captured on the datalog.
Now reference how much fuel the ECM / PCM asked be added or removed and add or remove the correct calculation yourself. The higher the number in the BLM table = the more fuel the ECM is commanding. A BLM > 128 = lean AFR, ECM adds fuel to compensate. BLM < 128 = rich AFR, ECM takes away fuel to compensate.
To fix your fuel tables Grab the cell you wish to change, as well as 3 immediate surrounding cells. Take your actual AFR / by your target, the answer gives you the percentage you need to change by. Multiply your BLM cell value by the % answer to make a change in the correct direction.
If your "answers" first digit is a zero you subtract fuel, if answers first digit is a one you add fuel by that percentage. Multiplying adds fuel, dividing removes fuel.
EX: AFR 10.3:1 & Target AFR: 13.2
1: 10.3 / 13.2 = .81
2: 81 out of 100
3: 100-81 = 19
4: the AFR needs a 19% change
5: take your current cell value X target percentage to get your target AFR.
OR option 2
Datalog with EEhack, open EEHack. Click analyze, run analysis.
1: Find in the cells where the EEhack analyzer tracked the BLM + or - %s
2: Now go back to TunerPro and correct those exact cells by the amounts provided by EEhack.
So now the vehicle idles and fueling is correct at all throttle ranges we correct timing.
1: Go to EEhack, click analyzer and click knock sensor
2:Areas in red are where the K.S pulled timing
3: Areas in green are where vibration, etc was picked up but timing was not decreased. Leave green areas alone.
Does this sound correct? Now I adjusted fuel as well as timing and should be good to go for all throttle and RPM ranges correct?
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