I googled, "smok v8 stick blinks 4 times" and got a link to this information:
1. 8 seconds protection:the LED light will blink 5 times when the power button is held for longer than 8 seconds,and the battery will automatically shut down the output.
2. Resistance protection:when the atomizer resistance is lower than 0.1 ohm or higher than 2.5 ohms,the LED light will blink 4 times and the battery will automatically shut down the output.
3. Low voltage protection:when battery capacity is lower than 3. 3V,the LED light will blink 15 times and the battery will automatically shut down the output.
If LED light blinks as below,then it is malfunctioning.
1.LED light keeps blinking.
2.LED light keeps lighting.
Solutions:
Please try to use coil or tank which resistance is between 0.1 ohm and 2.5 ohms.
This means that the coil in your tank is too low in resistance and needs to be changed.