After 15 minutes without juice, the KAM is erased (Keep Alive Memory) - Upon reconnect you fall into "Adaptive Strategy" mode. ie fuel trims and tran tables . It's a little complex. EEC likes to toy with the fuel ratio at random. It does this to run complex math equations. She is calculating how much fuel is required to reach certain lean or rich states.
Why? Because playing this cat and mouse game with the fuel ratio allows us to fine tune the engine parameters in other strategies. Confused yet? EEC cuts back on the injectors for a spit second and counts how long it takes for the HEGO to report back a lean environment. EEC leans and enriches at different amounts and get back different numbers. These numbers tell EEC if the engine needs a tune up, or if you’ve added a performance parts and allows us to actually alter the fuel amount delivered.
What do we do with those numbers EEC collected? Well there is a Table called “Adaptive Fuel Table” (makes sense huh?) This table is used as a multiplier, it is held over the master load table. It then multiplies each number in the master table to get a better control of fuel delivery over time. In a computer that has been just connected to the battery it is full of “1’s”, if you multiply the master table by “1″ you get the same number. I’m not good at math and I understand it, 14.7:1 X 1 = 14.7:1, simple!.
After many days of driving on the highway it begins to fill with multipliers like “1.2’s” and “0.9’s”, which will alter the master table. Don’t believe me? 14.7:1 X 1.2 = 17.6:1, and 14.7:1 X 0.9 = 13.3:1, and we just fine tuned our fuel curve without doing anything special.
Isn’t that cool? Well not always, this entire technology depends on the Oxygen Sensors being fresh, clean, new, and in good condition.
Damn! You both beat me!
Last edited by jbrew; 05-01-2008 at 08:15 PM.