wideband logging

[steveo]

im not really sure why it's such a pain, but with a wideband behind it, i can see how screwy CL really was...

[steveo]

thing is, even with my o2 median voltages set at 500mv, once the trims stabilize, it's still ~15.0:1 long average on the wideband in most operating ranges.

this sucks because when i was running pure open loop at 13.5:1 to get a good reference point for scaling tables, it was running so smoothly, and now you can feel it's just not quite in the right territory...

i think i might just make sure PE is always active when the thing isn't cruising, and tune PE to get my targets.

or should i try cranking the o2 voltages up a bit more? i bet it'll get pretty unstable if i push it too far. i at least want to get it closer to 14.7 under light accel..

or, maybe there are more parameters hidden somewhere that could be leveraged to force it into open loop during some ranges?

[EagleMark]

Did you ever find the Stoich AFR parameter? This could be the issue running E10 fuel? They are all set to 14.68 to 1 AFR. The first thing I do in a tune is set to 14.1 for E fuel and usually fuel trims go away.

The Stoich AFR Parameter is the first thing the fueling calculation looks at!

[steveo]

i dont think EE even has that parameter? you could be right...

where i live, we're E5, not E10, but that's 14.4 or so, and that's still just over 1% i think (just math in my head right now)

[steveo]

you know, thinking about it, i guess i actually dont mind it running a bit lean in closed loop. kind of a lean cruise feature. i just need to get it the hell out of closed loop when im not cruising, and that's doable. i already have idle, i'll just turn down TPS% to get into PE, and dial the enrichment into a range that i like.

[EagleMark]

i dont think EE even has that parameter? you could be right.

It would be the only GM ECM/PCM without it?

[steveo]

damn i wish i was better with disassembly. i'll look for it, though. i've found some misc. parameters before but this might be a bit out of my realm.

either that or im going to owe robert a whole ton of beer...

[EagleMark]

damn i wish i was better with disassembly. i'll look for it, though. i've found some misc. parameters before but this might be a bit out of my realm.

either that or im going to owe robert a whole ton of beer...

You and every other LT1 owner already owe him a ton of beer! Don't know if you did so but a message of thanks to him in your XDF or writeup would be in order.He's very modest and overlooked at all the work he has done for the DIY Tuning community! I'd bet he already found it on the V6... if you had that address or algorythm it would be a good place to start looking with TP 2d tools and use his Parameter. Then test... does LT1 show commanded AFR in data? Like when entering PE...