I recently picked up a used orca esc and it only works when hooked up to a sensored motor with a sensor cable.

It doesn't seem to want to work when I u plug the sensor wire.

Is this normal behavior for this esc?

Thanks all!

I'm not sure if that ESC was designed to have a sensorless mode fallback. But sensored ESCs are supposed to be used with a sensor cable at all times.

Did you read the manual?
As the manual state: Motor Type: Sensored 540 sized brushless motors

Also in the setup options nothing is written about running sensorless.