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While trying to diagnose a tricky car not starting problem I was asked to check if the spark plugs were firing at all.

I've found plenty of resources on inspecting the condition of spark plugs after removing them, and to do with diagnosing misfiring spark plugs, but not a test for a simple yes-no, are they firing at all or aren't they.

This is a first generation (1998) Toyota RAV4, which I believe means they are the coil-on type (could be wrong). They're deep set in a straight cylinder.

If possible, I'd like to test if they're firing without removing them, which would require specialist tools I don't have easy access to and might result in me damaging them.

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  • You should have 2 coil packs on the back side of the engine near the throttle body. Wires run to individual cylinders. I don't know how easy it would be to find locally but you can use an inductance spark tester. amazon.com/Lisle-19380-Spark-Tester/dp/B0002STS3U. – Ben May 2 '16 at 21:12
  • @Ben Good one on the coil pack. I thought they might be the coil on plug type. The newer ones are coil on plug. – DucatiKiller May 2 '16 at 21:33
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    @Ben your comment should be an answer – Moab May 2 '16 at 23:10
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You should have 2 coil packs on the back side of the engine near the throttle body. Wires run to individual cylinders.

I don't know how easy it would be to find locally but you can use an inductance spark tester.

enter image description here

http://www.amazon.com/Lisle-19380-Spark-Tester/dp/B0002STS3U

Another way to see if the coil pack is firing would be to pull a wire out and use either an adjustable spark tester.

enter image description here

Or take an old plug/pull one from a cylinder insert it into a plug wire and ground the electrode.

enter image description here
http://autorepair.about.com/od/troubleshooting/ss/coiltest-manual.htm#step2

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  • You should also answer the title of the question which is different, What I do is make extensions using old plug wires, pull the coil over off and connect it to the plug using the extension, then you can use those tools you posted. – Moab May 3 '16 at 0:42
  • I couldn't find any tools to do the former. It seems the minimal tools equivalent as employed by these west African mechanics is to pull a spark plug wire out of a spark plug well, stick a screwdriver down the tube and look for a spark when trying to start the engine... – user56reinstatemonica8 May 6 '16 at 9:23

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