Please Explain

[savage6]

CAN SOMEONE PLEASE TELL ME, IN ENGLISH I CAN UNDERSTAND, WHAT BLM'S ARE OR DO. I HAVE READ THE THING ON GNTTYPE AND ALL I READ WAS... BL!FIB@ FB@GFIN%B LL...16 CELLS...DFN SFGF*^GLN BXBL... SO ON AND SO ON. IT WASN'T MESSED UP IT JUST MADE THAT MUCH SENSE TO ME.

THANKS,

EVAN

 

[turbot2112]

when your blms are low your rich. when your blms are high your lean. 128 is right in the middle which is perfect . in a perfect world that is were you would want to be. there are 16 diffrent cells which vary with rpm.

 

[BoostKillsStres]

The cliff notes version is this: They are long term fueling values used in commanded injector constant calculation. 128 is the default value until the ecm learns differently. If the values are lower than 128 then the ecm is detecting a rich condition and pulling some fuel out and vise versa for higher than 128 for a lean condition. Usually if your BLM matrix is in a plus/minus 10 from 128 range your good to go but if your outside this its not a bad thing either as long as you don't hit the limits usually around 90 and 150 then the ecm can no longer adjust from there. Since our matirx grid is so small we move thru it very rapidly and several cells won't ever get used because your never in those ranges for it to learn different. Also some cells are only used on decel so those values are almost always lower than 128 but nothing to worry about.

HTH

 

[jimmymopower]

Man, I'll try but trying to answer what they are is gonna be....yeah. The only time you need to worry about them is if they are pegged in either direction at idle with the car at operating temp. A BLM reading of 95, for instance tells you that you have a condition leading the computer to believe it needs to take fuel away from the mixture. A reading of 160 is the opposite, the computer adds fuel. The later is usually caused by vacum leaks, bad check valves and such. These are the two extremes. The "holy grail" of BLMs is 128. This number represents stoikiometric(?) perfection. All that means is the computer is running a perferct 14.7 to 1 air fuel ratio. So what is a BLM? It is a numerical value given to a program the computer chooses to run depending on readings from the outside world. ie MAF,O2 sens, ect. This is how I understand them to work, but I'm not going to swear that this is a "proper" explanation. Hope it helps.