13B-MSP Engine Running Data
How I log a running 13B-MSP, what the oil metering pump's commanded step read in my Forscan logs, and the lubrication figures Mazda publishes.
How I log a running Series 1 13B-MSP, and what the logs show about the oil metering pump. It started as part of my EnduraOMP project. Mazda doesn’t publish the stock pump’s oil delivery and I haven’t measured it, so there is no delivery map here.
Logging set-up
- ESP32: reads engine speed from a Bluetooth OBD-II adapter (PID
0x0C) and logs an oil pressure transducer and an oil temperature sensor to CSV at about 5 Hz. It stores raw ADC counts, so the transducer calibrations must be applied before the values mean anything. I haven’t published figures from them. - Forscan: standard OBD-II readers don’t expose the pump’s commanded position (
MOP_POS), but Forscan reads it as an enhanced PID, along with coolant temperature, lambda and fuel trims, at roughly 100 samples a second.
What the commanded step read
Two Forscan logs from a warm engine: 111 s from idle (about 800 rpm) to 2,480 rpm with coolant at 80-83 °C, and 60 s up to 4,520 rpm with coolant at 86-88 °C. In both, MOP_POS read 7 throughout, at every engine speed.
Step 7 is Mazda’s fail-safe step. The logs don’t show whether the ECU was in fail-safe or the PID was just reporting a constant, and they stop at 4,520 rpm, so they say nothing about the schedule above that.
What Mazda publishes
| Item | Figure | Source |
|---|---|---|
| Oil pressure at 3,000 rpm, oil at 100 °C | 350 kPa (3.5 bar) | Workshop manual, oil pressure inspection |
| Oil pump relief valve opens | 441 to 490 kPa | Workshop manual |
| OMP stepper at start-up | Reverses 60 steps to find zero | Control operation page |
| OMP position switch changes | Between steps 52 and 53 | Control operation page and Service Highlights |
| OMP fail-safe | Stepper fixed at step 7 | Control operation page |
The OMP guide explains how these fit together, and the OMP Lab lets you step through the control logic.