How to check an ignition coil is working properly/in spec

[MmSadda]

I've had some issues with my car starting and whatnot as of late, and I believe my coils may be out of spec. What's the easiest way to test and make sure they're working properly? I've got a digital multimeter to work with (of course)

Any help is appreciated!

Thanks

Collin

[My5ABaby]

There's a test procedure in the FSM that involves resistance. That's the only one I personally know about.

[MmSadda]

Cool! Ill check out the fsm as soon as I get a chance. Thanks!

[Ptotherice]

One easy way to do it, unplug it, put a bolt where the spark plug goes (make sure it touches the metal in the plug wire, and then hold it near the body of the car. Now make sure you have PLENTY of insulation between your hand and the coil (like a plastic something to hold it far away from your hand). Turn off any of the fuel (pull fuses) and crank the engine over (it won't start) and look for a strong, loud, thick spark with a decently long jump. Don't hold it too close. That sounds harder than it really is, takes all of 2 or 3 minutes.... might try the fsm if it's easy.

[88turboii]

an easy way is turn the engine over while holding the spark plug connector slightly off the post and see if spark arcs. you could also simulate engine turning over by taking out the CAS and spin it by hand with the key in "run" position

to benchtest it, just find the pinout and use 12V on one pin, and briefly ground the other and you should see spark arc

[Max777]

guys, the bolth thing sounds stupid, a proper spark tester that will simulate running condition spark resistance only costs a few bux, and will give you the best result.

problem with testing spark the ghetto way: it takes 5K ohms of resistance for the spark to jump in open air, it takes 30,000 ohms of resistance for it to jump under compression in the cylinder

[t_g_farrell]

Coils are speced in the FSM usually for secondary and primary resistance. Just
use your DVM to measure them and see if they are in spec on all of the posts.

When I went hunting for some TFI coils, I brought my DVM with me to the JY
and did this as I was finding coils. Saved me a lot of trouble because the dead
ones were easy to see based on the resistance.