CVR_Rally

What would indicate a failing or failed ICM? Is it just no spark or weak spark?

marc abrams

Not seeing any spark in this tester:

Check your distributor cap for carbon tracking.

CVR_Rally

I filmed this on Dec 16th while trying to determine what was wrong.
I didn't notice before but it looks like it gets weaker as it goes on a bit and also misses a spark.
The cap and rotor are clean as a whistle.

marc abrams

What's the battery voltage while cranking? 9.6 is considered Min crank voltage
Pull the coil wire out of the distributor cap to see if you're still missing a spark. Should be able to jump a 3/8 gap.

CVR_Rally

12v but I've seen it drop to 10.5 but the temps have been so cold that doesn't help. I do have a charger on the battery when not trying to get it to run. Thanks Marc.

Jfrahm

You cannot really observe the spark on a loose plug like that and judge spark effectiveness except maybe on an old lawnmower or mini bike engine. It takes a lot more volts to jump the gap under compression (think of all that compressed air in the way). To simulate compression make the spark jump 10mm or so in the free air. The spark voltage rises until the spark jumps and under compression it might not actually get there. Instead the coil or circuit might fail or the spark may decide to jump a carbon track in the cap or who-knows-what.