AUTOOL Car Spark Plug Tester and Analyzer, 110V with Protective Cover and Double Hole 12MM Socket, Yellow

I ordered this item but I received only shell.You all should check item before packing.I disappoint this brand.

This spark plug tester works exactly as expected. It is very easy to set up and use, and it quickly helps identify whether a spark plug or ignition system is working properly. The adjustable RPM feature is useful for testing under different conditions, and the display is clear and easy to read. The build quality feels solid, and it has already saved me time diagnosing engine problems. Great value for the price. I highly recommend it for DIY mechanics and professionals alike.

I run a motorcycle shop, and I've always just had to use the ignition system of the bike I'm working on to test a plug. If a customer questions a plug I've replaced, it's really lame to do that kind of test as proof.This unit is amazing. I can test either one or two plugs at a time in either socket.I LOVE that kind of versatility.I find that a fouled plug will show its short on the lowest setting of this unit. The faster/stronger the spark, and the longer it sparks, will help the plug to spark in that same spot each time, so the foul condition appears less. Therefore, when testing a plug for foul/short/cracked ceramic/etc, always keep it on the lowest setting for the shortest time possible.A plug should never spark outside of its gap, so if a plug is observed to send a rando lightning anywhere else a single one time, that's all that's needed to condemn the plug.Then, I can prove(if needed) why the plug's bad using this fancy unit that tucks away so neatly! The power block completely fits into the clear cover, too. That might have been my favorite part!The manual is as simple as the unit, and also as complete as it could be. The quality of the packaging, manual, and certificate of conformity card is as impressive as the stringent quality control they put these units through(HIGH).Overall, I'm so very happy with this, especially at this price. 100% all around. I don't get to say that very often.

You can differently see if there is any difference in spark performance

It works. Can't check short plugs with it. Spark is small and hard to see unless in the dark. Not sure I would buy again. It does create sparks.

I bought this simple spark plug tester to troubleshoot why the engine in my car isn’t starting. Well two of my plugs are totally dead and the 3rd plug is on its way out, with the 4th and remaining plug working just fine. Now I know why my car keeps cranking but not starting.