Aug 9-10, 2026
Day 2 — The IACV Investigation
3 logs analyzed · 20 minutes of logged data · 8 stall/restart events detected
A methodology lesson, not just an engine lesson
This day produced two conclusions that were later reversed. First, a column tracked as "idle valve duty" was proven to be mathematically derived from RPM (correlation r=0.998) rather than a real sensor reading — the "IACV is stuck open" theory built on it was retracted. Second, several RPM spikes flagged as unexplained surging turned out, on full-resolution review, to be preceded by clean throttle ramps — they were intentional test revs, not valve faults. Both corrections mattered more for how later logs were read than for this day's findings themselves.
1173
Avg idle RPM (session-wide)
02Log-by-Log Breakdown
Session-wide statistics computed across each full log. These pool every idle-qualifying sample in the file, so they run higher than the narrow steady-state windows cited in the final project report — that's expected; this view shows total session variability, not just the best segment.
tfire7.msl
IACV unplugged for a comparison test. A duty-like column was tracked here that was later proven to be an RPM-derived value, not real valve position (r=0.998 correlation with RPM) — the 'stuck open' theory built on it was retracted.
MSL (limited channels)
Format
tfire8.msl
RPM spikes with throttle apparently closed were flagged as valve surging — later corrected: full-resolution data showed clean throttle ramps preceding every spike. These were intentional revs.
MSL (limited channels)
Format
tfire9.msl
Hard-starting episode with a WOT flood-clear attempt. Real idle oscillation confirmed in this one even after excluding throttle blips.
MSL (limited channels)
Format
* On stall/restart counting
Detected algorithmically as RPM dropping below 300 for a sustained period followed by a subsequent rise — a reasonable proxy for restart events, not a precise fault classifier. Treat as directionally accurate, not exact.
