Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity

Work very good

Saved me a very high priced remote service call for problems with my boat engines. I was haveing problems on one of my engines, it was running rough and would not go above 3000 RPMs, With the help of my boat yard mechanic (B&E in Michigan City Indian AWESOME team) on the phone I checked the plug wires with the above tool to find out that one engine was not firing on 2 of the 8 cylinders, through additional trouble shooting we replaced the plugs and all 8 are firing. This $19 dollar tools and $12 for 2 spark plugs and i am running smooth again. A remote service call would have cost at least $300. This tester is easy to use and calibrate even if I only use it ounce, which I wont, it was more then worth it.

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.

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.

bought it in hopes it would work for coil on plugs. tried it on a 05 gmc envoy, 00 mustang gt and a 17 ram. didn't read them at any angle. worked rather well on the spark plug WIRES on a 00 mustang v6 and a 73 challenger. even showed on a 51 Ford 8n surprisingly.