Engine monitoring on our own CAN bus (Chevy, F100)

No engine computer to read, so we add sensors on a new harness and our own small CAN bus.

Hardware

• Sensors: coolant and oil temperature, oil pressure, RPM from the coil or tach signal (opto-isolated), manifold vacuum, and a wideband air/fuel sensor with CAN output (AEM and others make them). Later: exhaust gas temperature, ignition timing.
• Nodes: small CAN boards (an ESP32 with its CAN controller and a transceiver) near the sensors; one bus, terminated at both ends, its own fused feed.
• Logger: a small NixOS box (as in the 4Runner) recording the bus; a display on the dash or a phone.

The ASP part: what to try next

The same shape as misra:

• Facts: readings bucketed by RPM and load (vacuum), e.g. "lean at wide-open throttle above 3000 rpm", "coolant climbs at idle, steady at speed".
• Rules: tuning knowledge, written down once: lean at WOT → richer power valve or jets; hot at idle only → airflow (fan, shroud), not the cooling system's capacity; rich at cruise → metering rods or air bleed.
• Constraints: one change at a time, and limits never crossed (temperatures, a lean limit under load).
• Output: the candidate changes, the evidence for each, and the cheapest next experiment, drawn like misra explain. Each change and its result becomes an episode.