ITEM NAME:2PCS Spark Plug Tester Ignition System Coil Engine In Line Auto Diagnos ZBD.2 Connect the black tip of the tester to the spark plug. Spark Plug Tester 2. 1 Turn off the engine and disassemble the spark plug coil. 5 If the ignition wire is intact, the indicator light flashes. 4 start the engine.
