[MR2] MK1 ECU quesiton

[Brian Knoblauch]

    Long Term and Short Term Fuel Trims (LTFT/STFT) are adjusted (on modern 
computer controlled) cars when parts/weather/whatever changes require the 
car to do so.  Only operates under closed loop, no effect on open loop. 
Takes, at most, about 5 minutes and it's fully adjusted.  That's the only 
thing I count as learning.  I don't even count timing retard due to knock, 
since it'll try the same advance next time you do the same thing, detect the 
knock all over again and have to bring it back...  (The DSM algorithm is to 
drop 1/3 degree of timing for each count of knock (and I suspect others are 
the same), so you usually end up with just a flatter than normal timing 
curve unless you have something that goes seriously wrong!).

--Brian
http://www.glmotorsports.net


> There is NO learning capabilty. They measure sensor inputs and then
> compare those inputs to preloaded maps. 99% of ecu's have zero learning
> capability and will not magically adjust for new parts by resetting. That
> is all urban myth. I have no idea where these rumors started and why so
> many people belive it. The only learning I have ever seen on an ecu is
> timing. For example a WRX will advance timing until it sees knock then go
> back a few degrees.