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How can I "check for spark" when my car doesn't start?

Sometimes, my car doesn’t start; or, it stalls and doesn’t restart (at least, not right away).

My mechanic wants me to check for spark when this happens. How do I do that? I know nothing about pulling wires and stuff like that. What can I do?


You could have an In-line Spark Plug Tester, like this one placed on a spark plug, and left, for a few days on the engine. It doesn’t affect the way the engine runs.
When the engine doesn’t start, or stalls and doesn’t restart, open the hood and observe the light of the Spark Plug Tester while someone cranks the engine. The Test lamp will flash, about every two or three seconds during cranking, if the spark plugs are getting spark. Tell your mechanic the results.

Strange, the OP and responder appear as the same person. BBS hiccup or stronger meds required?? :wink:

me thinks that hellokit is hoping more people will use the Search function and may be working toward not saying the same thing over and over again. -?

Either that or s/he just bought stock in S&G tools :wink:

Good catch. I’m going with the “needs stronger meds” theory.

cheaper hear, I have used these for 10years

All of you regular responders are just great! I think there are some REGULAR DRIVERS out there who, having a problem with their car stalling or not starting, would like some “How-to” for a suggestion that even YOU make, from time to time: “Check for spark”. Do you, or do you not? Do you have any mature ideas on the subject, or are you going to be juvenile, and unhelpful?

When I suggest someone to check for spark, I tell them to carry an extra spark plug in the vehicle. Then when the engine stalls, remove any spark plug wire and plug the extra spark into the wire and lay the spark plug on the engine. Crank the engine over and check for spark at the spark plug.


Yes, Tester, that’s good for someone who has some mechanical abilty; but, I’m looking for something that those people who have no such abilities can do. They, or someone close to them, can open the hood and make an observation, and report the observation to their mechanic.
When a mechanic has no symptoms on what may be happening intermittently, and when the systems check fault free, at the time of the checking, he could use information which points to a particular system on which to apply closer scrutiny; and, fixing the problem without throwing a lot of expensive parts at the problem.
Or, should mechanics use the old fall-back plan of: “Throw another part at it!”?

If you want to start a FAQ thread, or some such informative, general knowledge thread, you might consider at least cluing people in on your intentions. I think it is clear that a number of people had no idea what your intentions were. Getting huffy about the fact people can’t see what’s going on in your mind isn’t going to help either.

Personally I was comfortable with the idea of being juvenile and unhelpful. The alternatives require too much responsibility on my part.

In all seriousness, though, this forum has long needed a “FAQ” type of thing. E.g. for things like checking for spark or fuel; check engine light on; checking transmission fluid; etc.

My 2002 Sienna has an OBD-II fail code for any plug which misfires. Also for other parts of the system which fire the plugs. If you give your year; make; and model; you might get some more useful information on troubleshooting your car than “checking for spark”.

If that car is 1996 or newer, sounds like you need a new mechanic. Mechanic Files on this URL might have some recommndations for your community.

Autoparts stores will sell you a “Test Plug”, a special ($4) spark plug with an alligator clip built into it so you can clip it on something. It has a big, easy to see spark gap. By connecting any spark plug wire to the test plug and having some one crank the engine while you observe the plug, it can be quickly determined if there is any spark…

So, my friend, …what do you tell people who have “coil-on-plug” setups?

You tell them in order to determine if there’s spark or not on COP setup. they have to spend a lot of money on a scanner that can monitor the ignition system.


On my 5.3L V8, you could use the previously shown ‘plug tester’, as it has a ‘coil on plug’ setup and they are easily accessible.

Right…With most COPS, the test plug can still be used…

Perhaps I should have looked more closely before posting…

I do agree however that scanning is the best place to start for modern engines however I generally suggest getting a freebie at a parts store. There’s so much that can be learned from an OBDII system.