Need a little E10 help

[ls1x2]

416 base.hpt

Fresh 416 ls3 in a c5z. Only changes are going from a 347 to 416. It is a TT setup. 3 bar. SD with STFT enabled for drivability. Startup tune attached.

I realize I need to switch to lambda, but all my knowledge of what works for power and safety is still in AFR, so I am converting for now. Our fuel in htown is e10. The car actually idles smoother in open loop at 14.2 vs 14.7. I am tuning using my known good formula for my autometer 4v wideband. It works fine. The problem I see is that the computer wants to correct back to 14.7 via STFT no matter what I've tried. There must be something more than the stoich setting I need to adjust. What am I missing?

[tweaker47]

Post a log and config. What is your "known good formula"? Is the formula based on a stoich being 14.2 or 14.7? Is you gauge set to a stoich AFR of 14.2 and does it agree with your log value.

And oh boy... that VE table...

[ls1x2]

Post a log and config. What is your "known good formula"? Is the formula based on a stoich being 14.2 or 14.7? Is you gauge set to a stoich AFR of 14.2 and does it agree with your log value.

And oh boy... that VE table...

I meant to say the PID for the WB is known good to me. It agrees with the gauge. It is my understanding that the WB is just converting lambda to what it believes is the gas AFR. When fuel trims are off I can see 1.00 lambda on the gauge. With them on it goes to 1.02-1.03.

Nevermind the VE table . That was with LOTS of meth injection, and some cells had to be manipulated to get the fueling needed during fast turbo spooling.

I'll have to grab the log files tonight.

[tweaker47]

To get this straight... you are forcing 14.12 in OL with EQ ratio of 1.000 and the car idles smooth and you are getting lambda 1.00 right? Are you having big STFT in other air flow regions or just idle? You have tested the fuel to E10? It's a rarity anymore to find E0 but you never know.

You should log the airflow mode and O2 voltage. You may need to adjust the switching point on the O2's. This is the mV value the PCM switches between rich and lean.

Tables to look at:
Engine>Fuel>Open & Closed Loop>Airflow Mode>Mode vs. Airflow
Engine>Fuel>Open & Closed Loop>O2 Rich/Lean vs. Airflow

[ls1x2]

4.hplttix.cfg

Here is a log and config.

To get this straight... you are forcing 14.12 in OL with EQ ratio of 1.000 and the car idles smooth and you are getting lambda 1.00 right? Are you having big STFT in other air flow regions or just idle? You have tested the fuel to E10? It's a rarity anymore to find E0 but you never know.

You should log the airflow mode and O2 voltage. You may need to adjust the switching point on the O2's. This is the mV value the PCM switches between rich and lean.

Tables to look at:
Engine>Fuel>Open & Closed Loop>Airflow Mode>Mode vs. Airflow
Engine>Fuel>Open & Closed Loop>O2 Rich/Lean vs. Airflow

I was tweaking the tune just and idle and creeping speeds to get started on the tune. I was able to see 1.00 lamba on the WB and 14.2 AFR roughly. The car seems to like it, but once trims are turned on they seem to think stoich is 14.7:1. I believe the ethanol is 10% or close to it. There isn't even a gas only station for hundreds of miles. You can see the color in the fuel as well I noticed recently.

[tweaker47]

Any exhaust leaks? What's the status of your narrow band O2's? How old are they? B2S1 seems lazy.

[ls1x2]

This is freshly put together. I don't believe there are any exhaust leaks, and it does not sound like it. The o2's are original from 2002, but that is only 25k miles.

[tweaker47]

I suspect it is your O2's. B2 follows nicely with B1 but there are spots where B2 pegs rich while B1 still oscillates. That is why your STFT on B2 is a few factors higher. B2 averages 570mv and B1 averages 495mv at idle (should switch at 451mv at low airflows). I filtered out any values not at idle because I don't trust your VE. I believe B2 is toast and B1 isnt far behind. You could probably limp B1 by changing the switching points. I'd put in two fresh O2's and then tune the switching if need be if you still get negative trims.

[ls1x2]

I suspect it is your O2's. B2 follows nicely with B1 but there are spots where B2 pegs rich while B1 still oscillates. That is why your STFT on B2 is a few factors higher. B2 averages 570mv and B1 averages 495mv at idle (should switch at 451mv at low airflows). I filtered out any values not at idle because I don't trust your VE. I believe B2 is toast and B1 isnt far behind. You could probably limp B1 by changing the switching points. I'd put in two fresh O2's and then tune the switching if need be if you still get negative trims.

Thanks for the input here. I'm going to give that a go once I finish the OL tuning.