I agree with the pick up coil theory, they work when cold then when hot start to fail. You can test it by removal, heat, resistance tester. Some oil in a pot on the stove to emerse it in works for heat. (do that with pistons to fit the wrist pins.)

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!