How do I check for faulty spark plugs? CAN THIS WORK?

Question

Hi, I replaced 6 spark plugs (Bosch) in my 1993 nissan quest xe. How can I visually inspect if one of my 6 spark plugs are good or bad? I saw a spark plug tester:

http://www.kartsportnews.com/content/2009/prod_zaptester.html

how can I really do this test without the use of the tester?

Can I take off the spark plug, leave it hooked up to the plug wire, and then put ANOTHER spark plug in the hole were the "testing spark plug" was, then GROUND the threading of the testing spark plug to the chassis or battery negative terminal of the car, and finally start the engine and see the "dismounted" spark plug actual SPARK???????????????????????

CAN THIS WORK? Ive always wonder....could it work? it should work im guessing since the spark plug only archs the high voltage through...thats why grounding it properly to SEE the spark...

And the cylinder that had the plug removed, should only lower the RPMs...right? missfiring!

can it work?

Answer 1

Let's see, it costs $160. Spark plugs are about $2 each. That's 80 spark plugs you can buy. Divide that by 6 and if you change your plugs once a year, you can buy 13 years worth of spark plugs.



The way I test spark plugs is to run the engine. If it runs smooth, no problems. If rough and one of the spark plugs is causing the problem, when you short out the bad plug or disconnect it (watch the high voltage - use a tool), the engine operation will not change. If the spark plug is good, you'll get a rougher running engine. It could also be caused by a bad plug wire to that cylinder.



Spark plugs are very reliable. A visual inspection will tell you if they are bad, coated with oil or gas, etc. Google spark plug chart.

Answer 2

There is one other answer to your question to see if you get spark to the plugs and that is if you just hold the spark plug wires while someone turns over the engine to see if it has spark and your eyes light up everyone will know that you have spark to the plugs.Its only if you want all that electrical power going through you to ground when the engine turns over for testing.

Answer 3

You don't even have to put another spark plug in the empty hole and you don't have to start the car. Just let it turn over a couple of times while you are grounding the steel part of the plug. Make sure you use insulated pliers to hold the plug boot, or you will be in for a surprise.

Answer 4

My guess is you probably have broken down spark plug wires.they should be changed at 50 k miles if you want to test to see if your plug works remove it plug it back into the wire and turn the car over just tap it over or you will start the car and it will be extremly loud you motor will run the same rpms just without one plug so it wont run good .but a plug either fires or it doesnt. but it doesnt need grounded and dont touch it when its firing it can have up to 30k volts. change your wires i bet your car runs great

Answer 5

Yep, that will do it.....Check for spark......