what is lv8?

[oneslobuick]

I cant find any info on what this is or what it does.

 

[fast eddie]

It mesures the load on the motor

 

[ijames]

I've read that lv8 stands for load variable 8 bit, but that's not important right now . It is supposed to be a measure of how much air is in the cylinder, which is a measure of the load on the engine. It is used to index into the main timing table, and some other lesser stuff. Interestingly enough, you would think that after calculating lv8 and using it for timing the ecm would then use if for fueling, but noooo, it goes and repeats the same calculation in the fueling section before multiplying in some other terms to get to an injector pulse width. Must have been a committee project .

 

[oneslobuick]

my lv8 values are 150 at idle
they are supposed to be between 30 and 40 right?

what can i do to fix this problem?

 

[ijames]

What are your rpm, tps, iac, and maf readings at idle?

 

[oneslobuick]

RPM 850
TPS .44
IAC 38
MAF 06

 

[TurboDave]

Originally posted by oneslobuick
RPM 850
TPS .44
IAC 38
MAF 06

Wow, I was hoping to see something way out of whack that could be causing your outrageous LV8 value at idle, but nothing in those numbers above are out of the ordinary.

 

[ijames]

Ditto. I'm stumped for now.

 

[pacecarta]

all your info looks good to me

thought i would check some DS files i had on mine to compare


tps 0.44
maf 05 g/s
rpm 811
IAC 13
clnt 164
lv8 33


tps 0.44
maf 06 g/s
rpm 812
IAC 31
clnt 157
lv8 42

tps 0.44
maf 06 g/s
rpm 821
iac 39
clnt 164
lv8 39

 

[bruce]

Can you try another chip?.

LV8 is a function of gm/sec, and rpm. Either the LV8 scaler got changed, or the prom, has been zapped with static electricity, and there's no checksum. Those are the only two things I can see doing that. Other then RFI, ie bad plug wires, or some other High Voltge spark, or heater fan motor brushes being worn, and again arcing.

 

[GN owner]

Check this thread out over 2 years ago and explained in detail by Dennis Leek.

http://www.turbobuick.com/forums/showthread.php?s=&threadid=52885

 

[pacecarta]

thats a great thread ,
looks like you got your answer and then some back then
and to think i spent last night looking over the code trying to track down all the things it affects and is affected by ,
I should have known better to just used the search feature

 

[83ttypecooled]

I, never having been even close to being an engineer, only a lowly technician, have never been able to fathom the worth of the LV8 parameter. Obviously,there are a lot of discrepancies in the description of this parameter.I can't help you, sorry. Good luck!