This issue is not related to ecu. My suggestions:

1. Check if your starter bendix and O-ring need cleaning/replacing
2. Make sure there is no oil residure on the O-ring
3. Do not use WD40 can or spray lubricant directly onto the bendix assembly. (Apply droplets of sewing machine oil)
4. Check starter cable for good contact
5. Have you had any "Hot Start"?
6. Have you used any Co2 fire extinguisher on this turbine?

On your next start, please observe the spool down and see whether the compressor/turbine gradually come to a stop with small friction or do they come to stop suddenly. Please let me know.

Kraivuth S.