Coils?
09-26-2012, 08:59 AM
#1
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Coils?
So I think my coils might be going out and Im not sure if I tested them correctly.
I started the car and hooked up a timing light to each spark plug wire. The light activated with the front and back coil, but not the middle two.
Thoughts?
I started the car and hooked up a timing light to each spark plug wire. The light activated with the front and back coil, but not the middle two.
Thoughts?
09-26-2012, 09:02 AM
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Not a sufficient test. You need a coil tester that looks like a spark plug with a clamp on the side. One by one, disconnect a plug wire from a plug and onto the tester, observe the spark for consistency in color, brilliance, and frequency. If you find one or more that isn't firing smoothly and consistently, swap plug wires with one that was fine to rule out a plug wire failure on the one that was sub-optimal.
09-26-2012, 10:42 AM
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Actually, he didn't describe the spark needed. A clear blue spark is certainly the biggest clear point, but I don't believe that it's sufficient of a description. For example what if it's dropping every 10th spark completely? Should be able to pick up a pulsing or inconsistency visually.
I can see the spark varying by color, width, frequency, and brilliance. But really don't know how to describe in text a standard of what should be seen more clearly than what I already have. Even a video of a good one is questionable, due to the RPM changes, clarity of the video, etc...
Edit:
Team's DIY: https://www.rx8club.com/do-yourself-...-wires-222641/
The only references I can find regarding what to expect:
This video:
I can see the spark varying by color, width, frequency, and brilliance. But really don't know how to describe in text a standard of what should be seen more clearly than what I already have. Even a video of a good one is questionable, due to the RPM changes, clarity of the video, etc...
Edit:
Team's DIY: https://www.rx8club.com/do-yourself-...-wires-222641/
The only references I can find regarding what to expect:
It is essentially a special spark plug that requires the spark to jump about a 3/8" wide gap. The tester gap jump simulates a high load on the coil and wire. If either one is going bad it will almost always show up using this method.
When the engine starts a good coil and spark wire will result in a pulsing electrical spark across the tester end
Last edited by RIWWP; 09-26-2012 at 10:46 AM.
09-26-2012, 02:50 PM
#5
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IIRC, your Leading plugs should be firing at idle, while the trailing plugs are quiet.
Once you increase the rpms, all 4 should be firing all the time.
So, at idle, plugs 1 and 3 should be firing.
Above idle, all 4.
BC.
09-26-2012, 06:21 PM
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The last time I tested my coils I tested all 4, and all 4 were firing at the ~750rpm idle. I believe there is agreement that only the leading coils fire during starting, and I know they are all firing by idle, so a 500rpm switchover makes sense.
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