[335okc]

i started data logging my car again after i clean my WW tank filter.
meth is now flowing good, timing is good (for 91 oct)

my AFR and fuel trim is messed up tho
the afr seems non stable and the fuel trim is different from bank 1 and bank 2
here are some logs/chart

it used to not do this, is there something wrong with the sensor? injectors? hpfp ?
any input/suggestion/guesses are appreciated.

p.s. forgive me for the complexity of the charts, i tend to pack as much info as i can in the graph. please look at the values and color on the legend on the left to figure out which one is which.

[Tzu]

What maps are you running? Whats your meth mixture?

[335okc]

11-25 map 70/30 meth/water

[OpenFlash]

Originally Posted by 335okc

11-25 map 70/30 meth/water

Try resetting all your adaptions in the command center. And don't forget the DME Reset command at the end (Mode 3, command 3). This should sort out the delayed close loop fuel mode you got in the beginning of that run. The difference in bank to bank fuel trims is normal with chargepipe mounted meth nozzles. This is because meth isn't fully atomized before it goes into your manifold so don't get perfectly even distribution. We reduced the effect of this by oversizing our chargepipe (3.25" ID) and using two nozzles. But it's still there to some degree. Nothing to worry about that. Much bigger concern for those running big single nozzle (M10 or M14) with stock charge pipes. In those cases, you'll see a bank to bank variance of up to 20-25%.

Also, in your 2nd graph, the AFR oscillation is normal. That's how a closed loop fuel control system works.

Shiv

[335okc]

Originally Posted by shiv@vishnu

Try resetting all your adaptions in the command center. And don't forget the DME Reset command at the end (Mode 3, command 3). This should sort out the delayed close loop fuel mode you got in the beginning of that run. The difference in bank to bank fuel trims is normal with chargepipe mounted meth nozzles. This is because meth isn't fully atomized before it goes into your manifold so don't get perfectly even distribution. We reduced the effect of this by oversizing our chargepipe (3.25" ID) and using two nozzles. But it's still there to some degree. Nothing to worry about that. Much bigger concern for those running big single nozzle (M10 or M14) with stock charge pipes. In those cases, you'll see a bank to bank variance of up to 20-25%.

Also, in your 2nd graph, the AFR oscillation is normal. That's how a closed loop fuel control system works.

Shiv

Thanks shiv, i'll do that tonight. btw, some people say, after you reset adaptations, you need to do map0 first so the DME can learn better? do you recommend this?

[OpenFlash]

Originally Posted by 335okc

Thanks shiv, i'll do that tonight. btw, some people say, after you reset adaptations, you need to do map0 first so the DME can learn better? do you recommend this?

Nope. Unnecessary

[335okc]

ok, i did reset adaptation 12-3 and the lean spool up hasn't gone back since.
but, i still see wavy afr bank 1 and 2.
i heard this could be the foretale of aging sensor ? not responding fast enough and end up overshooting it?

[JamesM3M5]

Originally Posted by 335okc

ok, i did reset adaptation 12-3 and the lean spool up hasn't gone back since.
but, i still see wavy afr bank 1 and 2.
i heard this could be the foretale of aging sensor ? not responding fast enough and end up overshooting it?

At WOT or cruise? If it's oscillating under cruise, then it's normal like Shiv mentioned earlier. The closed-loop system intentionally oscillates in a small window.

[335okc]

under cruise, i just never noticed it. i guess i just never paid attention to the boring part before lol. just wanna make sure it's not something aging and robbing performance.

[JamesM3M5]

It should cycle between 0.99 and 1.01 lambda. It's the same phenomenon on a car with narrowband O2 sensors at idle and part throttle (<80 or so).