Ohming Resistance on Ignition Coil

[5zigen]

It says in the FSM that you can ohm ignition coils to see if they're bad. It says that 0 resistance is GOOD, and anything that's not 0 is bad.

What I was wondering is, if ohming the resistance on your ignition coils really is a reliable test. I haven't read anything about it on the forums either; faulty ignition coils are undiagnosible and usually more than one has to be replaced to "find" a problem.

I tested the resistance of all the ignition coils on my Q the other day, and about three of them read 1.xx. The others read in the 0.xx range.

Should the ones that aren't 0 resistance be replaced? Or is this even a reliable diagnostic?
Modified by 5zigen at 4:11 PM 12/1/2006

[elwesso]

best way is to narrow down the cylinder at fault and switch the coil packs and see what that does...

I dont trust that test, but did you try it anyway? If that test goes NG (meaning you get some resistance), you would throw a CEL.. coil packs dont usually fail in this manner I dont think...

The old school "switcheroo" is golden, IMO.

[Q45tech]

The problem is usually in the high voltage secondary winding and a breakdown in insulation in the winding or the extension boot..........very hard and expensive test equipment required to measure.......insulation robustness.

No simple $100 VOM will do some how you must simulate the real world conditions but observe and measure the 40,000 volt spark.

You narrow down the misfire to a cylinder, then remove and clean the unit and well, reinstall..............if still problematic you replace with a new unit.