Why the pump matters
Rotary apex and side seals rely on a small amount of oil injected into the engine. On later Mazda rotaries, the factory ECU sets that amount by moving a stepper motor on the oil metering pump, and a position sensor reports back how far it has moved. Leave it disconnected and the engine is either starved of oil or fed too much. The Elite handles both halves: a stepper output drives the motor, a feedback input reads the position, and a 3D table sets how much to meter.
Wiring tab
| Setting | What it does | Default / our advice |
|---|---|---|
| Feedback Input | Reads the pump's position sensor | Use an AVI (analog voltage input) |
| Output | Drives the stepper motor | Only stepper outputs can be selected |
| Drive Type | How the motor coils are switched | Low Side, which is what the Mazda motor uses |
| Range | Steps from fully closed to fully open | 200 by default |
| Max Speed | Top step rate in steps per second before the motor risks losing count | 50 by default. Don't raise it unless you know your motor can keep up |
| Invert | Reverses the motor's direction | Disabled by default. Use it if the valve moves the wrong way |
Calibrating the feedback
The Oil Metering tab tells the ECU what the feedback sensor reads at each end of travel:
- Monitor the AVI channel you picked for the feedback input.
- With the valve fully closed, note the voltage and enter it as Minimum Voltage. That becomes 0% open.
- With the valve fully open, note the voltage and enter it as Maximum Voltage. That becomes 100% open.
If the feedback goes the wrong way when you command more opening, recheck Invert before blaming the sensor.
Tuning the target table
The Oil Metering Pump – Target Position table sets valve opening from 0 to 100%. It is usually mapped in 3D against RPM and engine load, and up to 3D mapping is available. The logic is simple: low airflow (idle, cruise) gets small openings, and high airflow (high RPM and boost) gets large ones.
Our starting point is to follow the factory metering trend for your engine, keep the high-load areas on the generous side, and check oil consumption and plug condition over time. Too little oil hurts seals; too much fouls plugs and adds carbon.
The oil metering pump is one of the functions that must be wired straight to the ECU, not through a CAN expander. See ECU functions not suitable for CAN I/O.
Nexus owners should see the Nexus oil metering pump article. For more rotary advice, read 10 things you need to know about rotary tuning.
