More tuning questions- 4.3 TBI

[Bob Valentine]

At 11:40 PM 9/11/2000 -0400, you wrote:
>1)  When looking to change the VE tables, one should look for the Integrator
>values to hover around 128, then read the BLM's at that time.  Now, do low
>BLM's mean lean or rich?  What about high BLM's?

I wait for the BLM to settle out, use that since the integrator changes so
fast.   BLM's should be a little below 128.   I noticed a big difference on
tip-in with the BLM's around 125-126 instead of 128-129 at light cruise.     

Low BLM means the ECM is pulling fuel out from the current setting.   

High BLM is the opposite, ECM is adding fuel to the cal

>2)  Overall, my data captures indicate I have low BLM's (around 114) at low
>MAP/RPM combos, and high BLM's (Around 141) at higher MAP/RPM 
>combos, especially at WOT.  My O2 readings are constantly swinging back 

So your cal is a little rich at low map/rpm and a little lean at higher
map/rpm.

>(often wildly), except at WOT, where the O2 is pegged at near max mv.  Is it
>normal for highly swinging O2's?  And should I expect it to be pegged out at
>WOT, or can I get it back down somewhat?

Swinging is good, means the 02 is working properly.   Pegged at WOT is good
too, means you've got plenty of fuel.     Lean + WOT = burned parts.

>5)  Given that I have pretty low BLM's at low RPM (including idle), would
>that explain the very rough condition I run into at just off idle and low
>MAP?  It's very irritating, and I'm wanting to fix that problem first.

Remember to tweak the timing also, solved a lot of my idle/off-idle
problems.   Stock 350 chevy cal (aujp on a '730) has a lot more timing than
a 403 Olds needs or wants...  

-> Bob Valentine
-> bob at tecmark.com
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