Originally posted by Old School Nut
humm, so i supose it would be almost impossible to rig it up to energize a solinoid... humm
The knock sensor will not directly operate as a switch. If you're sharp with electronics it could be made to supply a signal to a circuit board which at a desired output from the knock sensor would use a transistor to send power to a water injection pump. Or it could pick a relay that would power the pump if the transistor and circuit board couldn't handle the load.