Just checked timming and TPS with LED lamp method. Barely had to touch to eliminate 2 lamps ang get only one on. When lamps disconnected and ignition on prior to turning over, there was a humm/vibration at the sensor mount. Once turned over and then shut off and ignition returned to "ON" but not turned over no more humm/vibration. Any ideas on what caused the HUMM/vibration?

Thanks for any clues. Car runs fine. Just bewildered here.