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Re: BLM numbers



Heres what *I* can see...

a BLM of 128 is neither adding or subtracting fuel to/from what the base PW
and other tweake are dictating... this much we know.  a BLM of 129 is adding
(129/128) or 1.00781 times (or 0.781% more) the calculated INJ PW. in
summary.. 0.781% per BLM value that is off 128.

your BLM numbers all look just fine if you ask me. Idle is being richened
up, which may be a result of a poor spray pattern or slower than stock
reaction times of the pintle. higher fuel pressure makes the pintle coil
have to fight more pressure, causing a slight delay... get em cleaned at
least. more fuel pressure also of coarse sprays more fuel in for a given PW,
so you'd expect a lower BLM at the zero cell.

A set of 23# injectors that were rated at 42.5 psi are really more like
24.5# at 50 psi. theres a straightforeward formula for gettting the effect
of FP, I'm embarassed that I cant pull it out of my head. setting the base
PW constant for 24.5's to 21# would have the effect of (before BLM's get
ahold of it) adding more fuel than the computer thinks its adding. the
effect SHOULD be lower BLM's.  what you may have is a situation where mods
you've done require 24# injectors, set to 24# in the prom, with 42.5 psi (45
is more appropriate i've read, but its still a trick to the computer) and
what you really need is tweaks to fueling to bring the BLM's down to
centerpoint. What you have is a few things set "wrong?" that are balancing
it all out.

o well.. rambling.  my posts usually draw out the correct answers so wait a
few.   ;-}


I'm going thru intensive BLM corrections on my TPI 383 right now. 150's and
160's in the cells.. working on it... trying not to "trick" the computer..
trying to set as much as I can correctly. a 14.5 AFR produces o2 bounces
that top out at 780 mv.. I dont want to set the target to 12:1 to acheive a
real world 14.7:1.. I want 14.7 to mean 14.7.  thats just me... and thats
"this week". ;-)

----- Original Message -----
From: Mark Romans (ICQ#66838770) <romans@pacbell.net>
To: <gmecm@diy-efi.org>
Sent: Saturday, April 22, 2000 11:08 PM
Subject: BLM numbers


> Is there a set % of fuel that BLM numbers represent?  In other words if
128
> is neither adding or taking fuel away, for each number in increase in BLM
> numbers how much fuel is being added on a % basis?
>
> My BL numbers read as follows
>
> 0 = 141
> 1 = 133
> 2 = 125
> 3 = 119
> 5 = ?
> 6 = 125
> 6 = 125
> 7 = 125
> 8 = 119
> 9 = 119
> 10 = 119
> 11 = 123
> 12 = 119
> 13  = ?
> 14 = 119
> 15 = 119
>
> I have the injector constant set for 21 lb injectors when I am running
23's.
> I have the fuel pressure set at 50 lbs with the vacuum line off and I have
a
> ported maf, which is why I think I am rich at idle.
>
> 1227165 in 87 Vet running 89 software.  APYP base code.
>
> I am planning on resetting the maf calibrations to correct the richness at
> idle and setting the injector constant back to stock.
>
> Mark
>
> --------------------------------------------------------------------------
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