Running way too lean.

[VonRottes]

Just put a little baby cam in a l76 222/234 .600/.575 115+3, got the wideband installed and I'm seeing 15-15.7 at idle. Currently has E50 on the tank with a flex sensor, that was to my knowledge working just fine before the cam.

ECM is commanding 11.8afr but not according to the wideband. Stft run in the -3 range ltft are closer to zero. Just for the hell of it I I added 30% on the maf table started up and saw a better 12.2afr but it immediately pegged the fuel trims and threw a CEL for the map sensor..

[5FDP]

Can't go off of AFR when using ethanol fuels. Your wideband is still using the gas scale. The commanded AFR will follow the content in the fuel but your wideband is still going to be based off the E0 stoich scale.

All you have to do is switch to lambda and it makes it much easier. You'd likely only need a few percent to the MAF/VVE to get it back to idling around 14.7 on the gas scale.

[VonRottes]

Okay, wow I feel really dumb 😅 I could have sworn the gauge I got could show AFR for ethanol.. nope just 0-5v output for anything other than gasoline.. 15.7 gasoline looks like it's pretty close for ethanol fuels so I guess I can resume tuning with that in mind...since I panicked.

[5FDP]

15.7 would still be a full point lean. You'd still want the wideband to show 14.7ish using it that way.

If you switch to Lambda you just need to worry about it reading 1.00. Every fuel is 1.00 using lambda, makes it real simple.

[Sub8]

15.7 would still be a full point lean. You'd still want the wideband to show 14.7ish using it that way.

If you switch to Lambda you just need to worry about it reading 1.00. Every fuel is 1.00 using lambda, makes it real simple.

Stoich value for e85 is around 9.5. E50 ~ 12

[5FDP]

Yes I know that. But all that means nothing if his wideband only uses the gas scale where stoich for any fuel in going to be 14.7. Thus the reason Lambda is better for this.

[Sub8]

Yes I know that. But all that means nothing if his wideband only uses the gas scale where stoich for any fuel in going to be 14.7. Thus the reason Lambda is better for this.

The sensor is looking for oxygen content. Gasoline scale doesn't mean anything.

At lambda 1 with e85 the AFR will be reported at 9.5.......

[blindsquirrel]

None of the tables used for tuning adjustments use 'AFR', it's all in EQ. AFR is dumb and just makes everything harder and more complicated than it needs to be.

[5FDP]

I have E50 in my tank right now. My wideband still reads 14.6-14.7 while idling when I have it on that setting. It will read right around 1.00 when I switch it to Lambda.

The only thing that changes is the computers commanded AFR, that will change to around 12.00 because of the E50 in my trucks fuel tank but the wideband reading will still show me 14.7ish when I have it on that setting. That is where you run into problems if you are trying to use commanded AFR vs actual AFR for a wideband error while tuning.

I'm still not sure what point you are trying to get across. The Ethanol sensor is always going to make the commanded AFR change but the wideband will not follow the commanded AFR because it doesn't know that I put E50 in the tank.