How to tune VE tables on a '98 ???

[Thedude]

I read somewhere that you supossed to use the secondary, or I think ELILive calls it "backup VE" table to tune VE on the '98 model LS1's ??
This true??

Also, any tutorials on how to adjust the VE using Fuel Trim's ?
I figure you could log LTFT , and map LTFT % (gm's/cyl) vs. RPM, that would tell you where to adjust the VE table, but can you just then copy/paste those values to the VE table to correct and bring the LTFT / stft closer to zero?

I don't have a WB yet, and it will be a while, mean time I want to get a halfway decent tune on the car as far as fueling (except for WOT, of course)
Please help a noob get started here !
Thanks

[wait4me]

Main ve is used when you are using the maf sensor.

The backup ve table gets defaulted to when there is a maf failure.

To tune, i just make the changes to both, copy and paste with " lables" from the main to the secondary makes it very fast to do.

Also make sure to note that there are other tables that swap when not using a maf sensor. Timing tables, spark adaptive learning, And another big thing to correct is the max line pressure on maf failure.

[87gmc]

Also can autotune be used on 98's?

[Dirk Diggler]

Yes it can you have to setup a map for the primary and secondary ve tables

[Black02SS]

Yes it can you have to setup a map for the primary and secondary ve tables

Shouldn't have to set up two maps, should only need one. If you make a primary map and "Copy with Labels" like Jesse mentioned, it should take the values for the secondary and plot them in with no problems.

[Dirk Diggler]

Yes it can you have to setup a map for the primary and secondary ve tables

Shouldn't have to set up two maps, should only need one. If you make a primary map and "Copy with Labels" like Jesse mentioned, it should take the values for the secondary and plot them in with no problems.

What about the 3% discrepancy we saw from logging the primary adn secondary tables separate

[Black02SS]

Yes it can you have to setup a map for the primary and secondary ve tables

Shouldn't have to set up two maps, should only need one. If you make a primary map and "Copy with Labels" like Jesse mentioned, it should take the values for the secondary and plot them in with no problems.

What about the 3% discrepancy we saw from logging the primary adn secondary tables separate

:? That is a very good point..... hmmmmm

[Thedude]

Main ve is used when you are using the maf sensor.

The backup ve table gets defaulted to when there is a maf failure.

To tune, i just make the changes to both, copy and paste with " lables" from the main to the secondary makes it very fast to do.

Also make sure to note that there are other tables that swap when not using a maf sensor. Timing tables, spark adaptive learning, And another big thing to correct is the max line pressure on maf failure.

So if the backup table gets used when MAF failure detected, how do you tune VE in SD/open loop mode? You can't copy the backup VE tables to the Primary tables, because the backup has less columns.
Man, the more i try to learn the more confused I become.
Why not just tune the VE with the MAF connected. That would compensate for both VE error and MAF errors together, right?
please help me understand, I want to get my LTFT's straightned out.

[J 98ta]

Get a wideband. I put it off for too long. Once I got it, and did the auto VE, I was happy right off the bat. Much easier, and much less time consuming. I have not gone back to the MAF yet, but I plan on creating the Main VE table in Excel from the secondary VE, then copy-paste. I figure I would avg the columns to create the additional 1/2 MAP range. IE: avg the 20MAP wiith the 30 MAP to get my 25MAP, and so on. Than I assume there may be some fine tuning after that.

Hope this helps,

'J

[dissonance]

I was planning on trying to tune my ve tables this weekend but the tables do not match as stated above.

So what steps would need to be taken with a wbo2? And once we get it nailed down we could update the added info to the autove tuning guide.

wait4me talked about timing, spark adaptive learning and line pressure on maf fail. I have been looking around in the cal and was unable to find these maf fail values or are you talking about turning off dtc’s?