Silly question but... change timing after swtiching ECU?
He is talking about the output of the pick up, it produces a very samalll AC signall when the reluctor passes it and it triggers on the positive peak of the sine wave if that makes sense.
Just a pic of one hope it helps.
![1024px-Sine_wave_voltages.svg.png 1024px-Sine_wave_voltages.svg.png](https://www.forabodiesonly.com/mopar/attachments/1024px-sine_wave_voltages-svg-png.1715786843/)