set the dial to zero and the light should flash on the red line on the crank pulley for 16 degrees. If you want to kno your exact timing, turn the knob until the light flashes on the WHITE line (has to match up with the crank pulley mark on your timing belt cover) and then look at what the knob is at, that will tell u your timing. Also make sure you jump the service connector or the ecu will change the timing.