Car: NA Miata (1990)
Engine: NB2 (BP-VE aka BP-Z3)
Speeduino: NA6 PNP
After initially getting the engine running on a modified NB8 base tune, I found that I had hot start sync issues: the Speeduino would not recognize any crank signal, resulting in the engine cranking but nothing happening (in TunerStudio, the "Cranking" indicator would not turn green).
I fixed this by changing the primary & secondary trigger edges to RISING (base tune uses FALLING). This gave consistent cold & hot starts.
I then set timing:
- In TS set "Fixed/Locked" timing to 10 degrees
- Use a timing light & adjust "Trigger Angle" until the timing light showed 10 degrees on the pulley indicator.
Then I re-read (for about the 4th time!) the setup instructions for 99-05 Miata. Which recommend a zero trigger angle and the new ignition mode. Reading the code, the new ignition mode *only* runs with zero trigger angle. So I followed the recommendation (and reset trigger edges to FALLING).
The engine started OK when cold, ran smoothly when stationary. However, it had difficulty revving under load & a test drive required a lot of throttle finesse. After parking, I could *not* restart the engine.
The above happened incrementally, over a couple of weeks during which time I'd also attempted to modify the Speeduino. We then tried:
- Reset trigger edges to RISING.
- Checked sensor voltage and continuity to the Speeduino.
- Checked trigger wheel clearance, orientation
- Swapped in known good crank & cam sensors
With hardware checking out, I decided to ignore the setup instructions and reverted to using FALLING trigger edges, the old ignition mode & 5° trigger angle. Worked great!
Disappointed the new ignition mode didn't work out, happy the car is up & running.