diff --git a/diagnostics/2026-06-29-no-start/README.md b/diagnostics/2026-06-29-no-start/README.md index d851332..62e55db 100644 --- a/diagnostics/2026-06-29-no-start/README.md +++ b/diagnostics/2026-06-29-no-start/README.md @@ -38,6 +38,24 @@ No engine P-codes, no FICM codes, no injector codes, no CMP/CKP codes. injector drive, cam/crank sync, and the FICM-to-injector path are all good when the engine is turning at running RPM. +## ⭐ EMPIRICAL CONFIRMATION (2026-06-30 crank test) + +Direct measurement with `--crank` and the verified `1446` ICP PID: + +**Peak cranking ICP = 376 psi** — below the ~500 psi firing threshold. +Full output in [crank-test-2026-06-30.txt](crank-test-2026-06-30.txt). + +This is the smoking gun. Truck cannot generate enough ICP during cranking +to open injectors → cannot fire on its own fuel → needs ether every time. +Matches the symptom-set perfectly. + +Side data from the same test: +- **FICM Main min: 48.0 V** — healthy, corroborates the meter. +- **Battery min: 10.3 V** — sag but adequate. +- 376 psi is "almost there" not zero → suggests a **partial** leak + (IPR seat / oil rail O-rings / partial STC crack) rather than a + fully blown STC fitting (which would typically show sub-100 psi). + ## ⭐ Key diagnostic finding: ether starts it every time Spraying starting fluid (ether) into the intake **gets the truck to fire, diff --git a/diagnostics/2026-06-29-no-start/crank-test-2026-06-30.txt b/diagnostics/2026-06-29-no-start/crank-test-2026-06-30.txt new file mode 100644 index 0000000..19ef16f --- /dev/null +++ b/diagnostics/2026-06-29-no-start/crank-test-2026-06-30.txt @@ -0,0 +1,36 @@ +2026-06-30 -- dedicated ICP-cranking test with the new --crank monitor. +Command: python obd_reader.py --crank + +===== 6.0 CRANK MONITOR ===== 00:40 1.8 Hz frame 51 +crank the engine q=quit r=reset firing threshold = 500 psi + + ICP [---------------------------------|------] -- psi + PEAK 376 psi BELOW 500 - keep cranking + + FICM Main -- (min 48.0) [DOC] Batt 11.8V (min 10.3) RPM -- + + ICP trace (psi vs time, last 18 samples) + 600 | + | + 500 |-------------------------------------------------- + | + | ####### + | ########## + | ########## + | ########## + | ########## + | ########### + +-------------------------------------------------- + +Verdict line at exit: + Peak ICP 376 psi -- did NOT reach 500 psi -- suspect high-pressure oil bleed-off. + +Headline: + * Peak ICP reached 376 psi during cranking -- below the ~500 psi + needed to physically open injectors. Truck CANNOT fire from cold + start on its own. Matches the ether-only-starts symptom exactly. + * FICM Main minimum 48.0 V -- healthy (corroborates the meter). + * Battery minimum 10.3 V -- sag but adequate. + * 376 psi is "almost there", not zero. HPOP is making real pressure, + just losing it. Suggests a partial leak -- IPR seat / oil rail + O-rings / partial STC fitting crack -- rather than a fully blown STC. diff --git a/handoff.md b/handoff.md index ede7577..a764fe0 100644 --- a/handoff.md +++ b/handoff.md @@ -71,6 +71,13 @@ The 6.0 needs, to fire: **good batteries → FICM ~48V → ICP ~500 psi → fuel bus problem. Verified PID set now in `obd_reader.py`; reasoning + sources in [pid-research.md](diagnostics/2026-06-29-no-start/pid-research.md). Added `--dash` (real-time gauges) and `--crank` (no-start monitor). +- **2026-06-30 ICP crank test:** ran `--crank` on the truck — **peak ICP + 376 psi, below the 500 psi firing threshold**. Direct empirical + confirmation of the high-pressure oil bleed hypothesis. FICM min 48.0 V + (healthy), battery min 10.3 V (adequate). Output captured in + [crank-test-2026-06-30.txt](diagnostics/2026-06-29-no-start/crank-test-2026-06-30.txt). + Next: physical inspection (IPR valve first, then STC fitting, then + oil rail O-rings). - Pushed to `git.jpaul.io/justin/ford-obd`, branch `main`. ## To resume with Claude from the cab @@ -80,22 +87,28 @@ no-crank, hot vs. cold, what changed before it died, and FICM/ICP readings if yo ## To resume at the truck (2026-06-30 state) -The diagnosis stands: high-pressure oil (ICP) bleeds off during cranking; -HPOP outruns the leak once running. The toolchain can now confirm this -directly from the OBD port. Top actions, in order: +The diagnosis is now **empirically confirmed** — `--crank` measured peak +ICP 376 psi (need ~500 psi to fire). High-pressure oil bleeds off during +cranking; HPOP outruns the leak once running. The 376 psi reading suggests +a **partial** leak rather than a fully blown STC fitting. Physical +inspection, cheap-and-easy first: -1. **`python obd_reader.py --crank`** during a short crank. A healthy 6.0 - builds ~500+ psi ICP in 1–2 seconds. If ours stalls below 500 psi or - builds very slowly, that confirms the bleed-off and is the smoking gun. -2. **Probe the FICM PIDs that were outside the scan window** to validate - the documented `09xx` family on this truck: - - `python obd_reader.py --pid 09D0` (FICM Main, expect ~48V) - - `--pid 09CF` (Logic, ~12V), `--pid 09CE` (Vehicle V), `--pid 09CD` (Sync) -3. **Visual under the valve covers + STC fitting** — the likely physical - source of the leak. STC fitting is the #1 6.0 culprit for this pattern. -4. **Widen the brute scan** to round out the verified set — - `python obd_reader.py --scan 0900-09FF --scan-log scan-09xx.txt` and - `--scan 1600-16FF --scan-log scan-16xx.txt`. +1. **Pull the IPR valve** (~15 min, ~$0). Bolted into the back of the + HPOP, top-rear of engine under the turbo. Inspect screen for debris, + pintle/seat for wear, O-rings for cuts. A leaky IPR seat causes + exactly this "partial pressure" symptom. +2. **STC fitting visual** — between the heads under the turbo. Look for + wet/oily film at the fitting joint. Ford TSB; classic 6.0 wear item. +3. **Pull valve covers** and inspect high-pressure oil rail O-rings on + each head. Bigger job but common 6.0 leak path. +4. (Once a repair is attempted, re-run `--crank` — peak ICP should jump + to 500+ if the fix worked.) + +OBD-side follow-ups (lower priority now that we have the answer): +- Probe the FICM 09xx family: `--pid 09D0` (Main, ~48V), `--pid 09CF` + (Logic, ~12V), `--pid 09CE` (Vehicle V), `--pid 09CD` (Sync). +- Widen brute scan: `--scan 0900-09FF --scan-log scan-09xx.txt` + and `--scan 1600-16FF --scan-log scan-16xx.txt`. ## Open follow-ups Detailed action list lives in