Just a quickie.

running my B20 on obd0 with BRE
using a lm-1 and ostrich + datalogger etc (live editing as i drive etc etc)

i have the idle spot on, also the part throttle cruise fairly well mapped.

the problem i have is with part throttle cruise. i try to tune the first 4 columns with 14.7 afr. at say 3500rpm at 70mph it will hold 14.5 afr for a while, then jump up to 15.1, then maybe drop down to 14.3, then back to 14.7 (this is closed loop so no O2 sensor running) it stays at least a few seconds on each value

i know the ecu interpolates the values between 4 cells but if i increase all 4 even by 1% it dumps to much fuel in, if i try just increasing a couple or what i think the problem one it changes the cells next to it or the afr in general.

am i trying to be to perfect in getting a spot on 14.7 cruise or is this just normal to find that the afr does fluctuate slightly when reading 2 load points and averaging them? with the O2 sensors turned back on the ecu will then go back to keeping it on 14.7 correct?

any tips of info you could give would be great :D

Cheers

 

how smooth is the map from one cell to the next? Are the surrounding cells much more drastic changes or have you smoothed and interpolated the entire column and the row? These things can cause the jump you are getting.

 

they are reasonably smooth

interpolating. should i do a full row and column at a time from the very bottom to the very top?
or should i only go from left to right across a specific rpm band?

i have tried it but as soon as i do it leans out the entire part i have interpolated and i have to start from scratch again or re-open the file