[lucasborka]

Trying to troubleshoot an oscillating stft on my 435i stage 2+ fbo, stock Intake.

On hot idle it seems to bounce up and down between -0.9 to -2.5. All within 3% which is good, but I feel the idle is slightly on the harsher side. Afr at 14.5, so it seems to me it is running slightly rich. LTFT are very stable at 0.03

No issues at WOT or cruising, I’ve done smoke test. And my valve cover is 12k miles old only.

Idle: https://datazap.me/u/lucasborka/stft-oscillating

Wot: https://datazap.me/u/lucasborka/stag...og=0&data=3-21

[luca.aluigi]

Hi Lucasborka, i share you my datalogs:
Idle: https://datazap.me/u/vetus/log-17113...27-28-29-30-31
WOT: https://datazap.me/u/vetus/wot-stage...29&zoom=22-196

Stage 1 MHD N55 EWG, Catless, Wagner evo II FMIC, Turbo inlet MST V2, MPPK lower airbox, GFB DV+ diverter valve.

your logs seems to me normal, at idle STFT is always "sinusoidal" even the timing between the 6 cylinder have a small offset. Pattern that i see regularly on my logs. In conclusion mine and your logs are pretty similar.
Your manifold Boost is just a little bit below the boost target.
what engine modification do you have?

[lucasborka]

Originally Posted by luca.aluigi

Hi Lucasborka, i share you my datalogs:
Idle: https://datazap.me/u/vetus/log-17113...27-28-29-30-31
WOT: https://datazap.me/u/vetus/wot-stage...29&zoom=22-196

Stage 1 MHD N55 EWG, Catless, Wagner evo II FMIC, Turbo inlet MST V2, MPPK lower airbox, GFB DV+ diverter valve.

your logs seems to me normal, at idle STFT is always "sinusoidal" even the timing between the 6 cylinder have a small offset. Pattern that i see regularly on my logs. In conclusion mine and your logs are pretty similar.

Thanks a lot for reference!

Nothing to worry about then, only slightly richer at idle. But minimal 😁