92 ignition coil testing

does anyone know how I can test a ignition coil on a 92 Lesabre? I think I may have a bad one. The car is missing just off idle and under a load. I have replaced the plugs and wires (they needed it) I think it may be a coil or a camshaft position sensor.
How can I test the coil?

I usually use a spark tester connected to the spark plug end of the ignition wire & grounded. While cranking the engine, observe the spark. If you see a crisp blue spark, the ignition coil is working properly. If you only see a pale yellow spark, more than likely, you have a weak coil.


When testing the coils primary resistance, use a paper clip to insert into the primary side terminals. (Female - Bottom side of coil) and place the two leads of your DMM on these to check resistance. On the secondary side, simply place the leads across the two coil output terminals and set your meter for reading K-ohm. The specs for resistance are:
Magnavox ignition: Primary (ohms) = 0.5-0.8 (ohms).Secondary = (k-ohm) 9.0-12.0
Delco ignition: Primary (ohms) = 0.5-0.9 (ohms) Secondary = (k-ohm) 5.0-8.0

thanks for the quick reply. How do I know if I have the magnavox ignition or the delco one?

OK thanks. I figured out I had the delco type. They OHMed out ok but I found a crack in the same place on all 3. Replaced all 3, now everything is good!

Good find! It is very unusual for all three to have a “crack”! I wonder if someone sprayed cold water on the coils while hot, or over tightened the coils at one time. Another good way to find this sort of problem is to spray a mist of water around the secondary ignition components with the engine running in a dark place. If you see fire arching, you have a problem. The fire will always seek the path of least resistance, and that is the nearest ground!

I dont think any water ever got sprayed on them. I've had the car for awhile and I do all the work on it. They did'nt appear to have been over tightened. Once I removed the top coil for testing with my multi meter the crack was very evident. It looked like it had been cracked for some time. It OHMed out ok so I OHMed the second one on the car. It OHMed out ok too but I wondered if it might be cracked so I took it off and it had a crack in the exact same location. This made me think "I wonder". I pulled the 3rd one and it also had a crack in the same location. We had some real wet weather that day and the car started to act up. Thanks to you I was able to find it and repair the car. Thanks!