Quick(?) question -- how long does it take for long term fuel trims to change? For instance, if you do something like put a slightly larger MAF on (just an example) and it keeps correcting the fueling in closed loop, at what point do those correction values get stuck into the long term table?
when i did little ST tuning, AF trim learned (long-term) began to slowly change in very small increment as I drive around normally in closed loop. It just doesn't update constantly.
What I'm looking for is the algorithm/formula for the delta change... in other words if you're seeing a constant +3% or so on immediate trim, how long before long term / constant trim hits that point.
As far as I know there is no set formula at least one that the manufacturers tell us about.Some one who studies there engine data might have more info.Also, does it always read the same?.I thought most cars will vary under different driving conditions.We are always told not to stare at the scan toll while driving(actually not to try to read it) and it usu. is a pain to get someone to ride along.
For a burrito I'll explain it all to you Wow, wouldn't that suck if nobody shared... Anyway Long-Term Fuel Trims are kept in a table in the ecu based on MAF voltages. Cobb is working on us being able to see this table, likely a 12x1 with MAF voltage and LTFT. It only takes a few seconds of staying at the same maf voltage for the LTFT to start to move based on the STFT. So the short and sweet of your answer is a few seconds, but only if you are holding the car still at that maf voltage. Chipotle burrito bowls are $5.78 and my paypal is my e-mail address SS
hmm...maybe a good idea is to wait for scott to share all of his knowledge about tuning, then tune myself....oh wait...i dont know if it is possible to learn all of his knowledge this fast. Thanks Scott for all your help, see you when I graduate and get a job haha