High BLM's and O2's ????

[dsa87gn]

I just took the car out for a run and am getting something I don't quite understand.

At part throttle I have BM's up in the high 140 range and the O2
number are over 800. the car is pulling very strong and T-Link records no knock.

I'm a new tuner and confused with these #'s, can anyone help me out ?

 

[turbo buicks]

not sure on the o2 numbers but at idle my BLM's were 150-160 and you could smell the gas. the guys told me my car was running way lean and the computer was dumping in too much fuel. i might have a leaky injector causing it.

 

[WarpSpeed]

O2s aren't too bad at part throttle. blms at 140 maybe mean there's a slight intake leak between the MAFs and turbo, but it's prolly ok


[ at idle my BLM's were 150-160 ]

The computer is adding fuel, because it thinks it's lean. Could be a MAF sensor problem.... Prolly not an injector, if it was, the computer would be pulling fuel and the BLMs would be below 128, prolly.

 

[Carolinaturbot6]

For the archives...
"There is nothing wrong with your chip or fuel delivery system, even in normal driving, when your BLM (Block Learn Mode) numbers are anywhere between 110 & 145. The car will still be running stoichiometrically correct no matter what the BLM numbers show, as long as they are between 110-145. Numbers below 128 show that the computer is taking away fuel & numbers above 128 show that the computer is adding fuel. In either case,the car is not running rich or lean! The BLM numbers basically show what fuel corrections the computer is making in order to keep fuel delivery stoichiometrically correct. BLM numbers will vary with types of gasoline, weather, & at idle when you turn on the a/c!
Now if your scan tool shows BLM numbers always way below 128 or way above 128, it shows that some fuel correction is necessary. Often this can be adjusted with the fuel pressure regulator. But still, the computer is working (only "harder") to keep the fuel mixture stoichiometrically correct. If BLM numbers are always below 110 or always above 145, that's when you start looking for a fueling problem!"


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[ALBERTAN]

When you hear people talking about tuning for O2s in the 780 range, they are talking about the value at the end of a quarter mile run. The number will continue to drop through third gear in a run. HTH.