how do i check for spark?

Question

i would like to know.

Answer 1

Unplug a spark plug wire and lay it close to a bit of grounded bare chassis or body metal, have someone crank the engine and watch to see if it sparks.

High voltage, as used in car ignition circuits, doesn't actually "go through" rubber insulation, it actually "walks" over the outside surface of the rubber to a grounded connection (you). It doesn't matter how thick the insulation is, unless it's a couple inches thick, or more.

(You could do what my neighbor did and hold a spark plug wire in his bare hand while somebody else [his wife] cranked the engine over... after he let go and quit dancing around he eventually diagnosed the problem [bad fuel pump], but I understand he had a bad aftertaste in his mouth for a week.)

That will tell you if you have spark, but if won't tell you if it's sparking at the right time. For that you need a timing light or a (fairly expensive) engine scanner.

Spend a few dollars on a service manual specifically written for your car, or have it fixed by a real mechanic.

Answer 2

Soooo.... Am I the only person that pulls off spark plug boots by hand? What's the big deal? Somebody actually shared an anecdote? Good grief, guys. Don't be so chicken.

When you're testing for spark, you may well get one through you. It won't hurt you. Loads of voltage, but not enough amperage to hurt anything.

All the methods mentioned are good. It's nice to use an old spark plug, but it has to be grounded properly. There is a tool made especially for that. The tool is kind of a spark plug with a ground clip. It's also useful to stick a phillips screwdriver into the boot, and then make the spark jump from the screwdriver to ground.

It's better to see the spark than to go by how far it can jump. You can tell a good strong one by color. If helps if it's not so bright when you're checking.

Answer 3

I don't recommend laying the spark down against the metal surface. This test was used on older model vehicles with distributors. However the high voltage produced in today's vehicles could cause ignition module damage. Your best bet is to use a spark tester.

Answer 4

Carefully pull one of the boots off the spark plug with a pair of rubber gripped pliers.... then hold the end of the boot to something metal in the engine compartment.... it will arch and you will see a spark... if not then you have a bad wire or cap and rotor etc

Answer 5

I use a checkspark tool only $32.00 online just clip it on the plug wire and turn the engine over. It works on all engines that have spark plugs and wires. I love it it also tells you what's wrong withe the spark...shorted...open....nonexistent...or good no problem...no risk of shock or burns . It's sweet!!!! Randy

Answer 6

The best way is to pull the plug and lay it against bare metal. High energy ignition can blow right through rubber griped pliers and knock you on your kiester.

Answer 7

some people don't have the few Extra Bucks ,, that's why they ask Questions... some people are willing to give any advice whenever possible,,, I know I do when I can... ****,,, if I had extra money,, id just buy a new car

Answer 8

pull a spark plug wire off by the boot not wire,put a screwdriver in the end,ground it somwhere,DO NOT HOLD THE SCREWDRIVER,if its getting fire you will see it.

Answer 9

so glad that I found this question already answered! it is like you've read my thoughts!

Answer 10

Thanks for the answers.