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.