66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity

Work very good

Great tool

Very handy tool. Accurate. Just remember that this is a firing tool, if your engine is not capable of firing ie. Too much fuel. It will not show you the energy coming from the coil.

Quick and reliable Spark Plugs, Cables and Ignition Tester. We use these daily to verify spark plugs, cables and ignition fault codes from OBDII scanner before inspection and removing from engine. Easy to use and good value. Sensitivity dial is a little loose so it is important to test and experiment with different settings for domestic and import cars.

This is the second one of these that I've had. I should have never let a co-worker borrow the first one. He quit and I never got it back. It's a nice little unit for testing to see if you have a plug that's firing like it should. It has a a clip so can stick it in your pocket. A thumb wheel that you can turn the sensitivity setting up or down with. The pocket clip acts as an on switch. Just hold it down and the green light comes on. Put it next to a plug wire or a coil tower or a spark plug boot. And if getting spark. The green light will pulse red every time it fires. The top part of the pocket clip hold in the three coin batteries that makes it work. The first one I had the batteries lasted for a long time. (several years) Fairly rugged. Had mine fall out of my pocket onto a concrete floor many times and it never effected the way it worked. Handy device that I feel is well worth the money.