OTC 6589 Electronic Ignition Spark Tester white

His quality tool works amazingly for hei and dis systems and is a necessity

Excellent tool, I don't even consider using a screwdriver or additional spark plug to test coils, a real test anymore. Coils sometimes like to get weak over time, and cause occasional misfires. You can't really test if it's 20% weaker than its supposed to be. It will still appear to be a good spark. Unless you use the OTC spark tester, it requires the coil to output a much higher voltage. Similar to under high load conditions. Sounds like I'm trying to sell this tool, but it saved me a lot of time today on a Ford 5.4 with 4 coils that didn't pass on the tester. They all had decent spark but not enough apparently. Replaced all 4 of the ones that tested bad, and now it runs great. There's no other way I would have known that. The only issue I've had with it is the end that snaps into the spark plug wire kept unscrewing over time, a little loctite should keep it in place though. Also the porcelain can get dirty, I use brake cleaner and a clean paper towel or q-tip to wipe it clean again. I bought this about 2 years ago, it's helped me a lot but really saved me today. I paid $13.84 here on Amazon. Paid for itself over and over. Edit 2021: the clip fell off recently, since it's really only hung by a small metal tang. Problem is, the spring flew somewhere and now I can't use the clip anymore. In order to ground it, I have to attach a small jumper wire to it now. Which I had to do that occasionally anyway, since cars have so much plastic. I'll probably find another spring eventually, and cut it down if I have to.

Excelente producto, muy útil

Recommend, shows how much spark you have from spark plug coils to spark plug. Fast delivery, good product. Happy thanks

I’m not a professional mechanic, but I pretend to be one. We’ve all done it before—using jumper cables or vice grips or any other means of grounding out a sparkplug to check and see if it has spark. Well, that’s basically what this thing is. I’ve only used it once (on a ’96 Toyota with coil on plugs) and it worked like a champ. I don’t know if the shape of the porcelain and the gap it has to jump affects how loud the “pop” of the spark is, but you don’t even have to see the spark to know it’s working—you can hear it. I know there are some comments about this unit not working with older style ignitions, but let’s be serious. If you’re working on a 65 Ford, you probably just hold the spark plug in your hand and crank the engine to see if it’s working. We’ve all done it….at least once to our little brother. It’s a little on the pricey side, but as long as you don’t drop it on a concrete floor or throw it against the wall, it should last you many years (or 100,00 miles, whichever comes first). Very happy with my purchase and I wouldn’t hesitate to buy again.