With our non-turbo engines running on two spark plugs per cylinder, some/most would be hard pressed to even notice if a spark plug or ignition lead had failed.

I came across this tool; I can't remember where, but after checking other options, I decided to go for it.

Since our spark plug leads are in close proximity to one another (as they are on many vehicles), even at the valve covers, I needed to adjust the sensitivity of the tool to prevent an adjacent plug from giving me an indication of another than the one I was testing. I wrapped the probe with aluminium foil and left 1/4" of the end exposed.

It worked great and confirmed all 12 spark plugs were firing. Not bad for 16 year old spark plug caps.

A couple of sources for the OK Spark at good prices are Amazon and National Tool Warehouse.

 

That is one expensive tool. You can also buy attachments for more higher end voltmeters that will do the same for 1/4th the price.

I agree with 12 plugs going it can be hard to tell what one is not doing so well. Did you check from under the car, or at the cap?

 

To some it may be, but it sure beats paying shop rates. I've always said tools don't cost you money; they save/make you money countless times over.

I checked each at the spark plug cap. To make sure I wasn't getting a signal from a nearby ignition lead, I'd move the probe away a few millimeters and confirmed that the LED stopped flashing. This after I wrapped the probe with tin foil.

 

Uhhh....How about $15.00? http://www.grainger.com/Grainger/WES...0Tools-_-1EKP5

 

How does it perform?

Its too bulky to use further back in the engine compartment, so I guess you use it at wires at the distributor cap.

Have you checked that the wire doing the flashing is actually the wire being tested and not the one right next to it that is activating the tester?