What lowers the BLM number, increasing or decreasing the fuel pressure

[transampacecar]

My BL number is 135 with 42 psi with the vacuum off.
I cant remember whether increasing or decreasing the fuel pressure lowers the BL number. Anyone know ?

 

[TurboToy]

135 is lean but is that at idle or WOT? needs fuel to bring it down but whats the rest of your combo?

turbotoy

 

[transampacecar]

I thought that over 128 was rich ? Am I wrong ?
Anyway, the rest of the numbers are where they should be. The 135 was at idle with the engine at operating temperature.
I am getting around 1.6 of knock at WOT at the top of 3rd gear running 100 octane and about 20 lbs of boost. Will decrease the boost tomorrow.
But again, isnt 135 rich instead of lean ?

 

[Swede2]

No its lean, not rich.

Daniel

 

[bkoons]

BLM higher than 128 means that the ECM is adding fuel in addition to what the learned fuel curve thinks it should based on the variables (TPS, RPM, LV, etc.). It does this because the O2 sensor is indicating a lean condition. In my limited experiance, reducing fuel pressure has not brought a high BLM at idle down (I assume your reading is at idle in closed loop). A vacuum or exhaust leak or malfunctioning sensors (O2, MAF) might be the cause. If turning fuel pressure down doesn't help, do a search on "high BLM". Razor did an excellent write-up on how to find the cause.

 

[83ttypecooled]

Block learn

Hi,
!35 is not outrageously lean, I doubt that a vacuum leak exists. Again, we don't have enough info. If you have an adjustable regulator, give the car a couple of pounds extra and see what happens.