Simple and inexpensive way to check for spark with coil on plug or other types (distributer, etc).
This is similar to a standard spark tester but also includes a shaft for inserting into recessed plugs. The shaft part is essentially the same thing as the cop boot / wire / spring devise, and it makes wash work of getting into the plug. For my engine (5.7 hemi V8) I inserted the smaller end of the shaft and it worked perfectly.
I also used slo-mo video on my phone to record and the watch / listen to the engine and it seems to help.
Screen grab below. Note I have two plugs per cylinder / coil so I had to get two testers. Odds are you only need one.
Provides information not available with OBD II code reading devices - pinpoints if there is a spark plug, plug wire, mechanical, fuel injection or electrical problem. Shows a duplicate view of the ignition spark so technician can visually check condition of ignition system at each cylinder. Use for testing newer vehicles with recessed spark plugs and conventional and coil-on plug ignition systems.