quneur

You could have gotten a bad ignition coil but it sounds like a short somewhere. If you know its the coil, start from there and work your way back. Make sure there's no burned wires or connections.

How did you test the coil? Preferred method is using a clamp meter to test voltage (I suppose you could use a spark plug attached to wire to coil although I don't know if a continuous spark would damage the plug.) But if just looking at spark plugs then it could be the wires, distributor cap/rotor or distributor itself.

DFlintstone

The led is polarity sensitive, (just won't flash backwards)....not every led works. I tried one from a $ store flashlight and it didn't seem to work...

imchestnut

So here is an update. I wasn't sure how to test the coil so I put one of those LED spark plug light testers on it and grounded it. Nothing. I swapped out the coil with a buddies working coil and it fired right up last night. It started five or six times. The "new" coil won't work at all. The ICM was good when I tested it at the parts store.

I went back out tonight after having it sit overnight, and, as usual, it would crank but not fire up until I charged the battery for a bit. It seems super sensitive to a slightly drawn down battery? I'm testing that theory right now by leaving the lights on for awhile. I forgot to check the voltage before I threw on the charger. When I drove it around the block the battery voltage was 12.7.

Is it possible that the battery has enough juice to run the starter but doesn't have enough to also run the ignition coil to get spark?

I also replaced the ground wire on the back of the block (it was the original mesh ground strap/joke), cleaned the connections and degreased everything I could.

67 GMC

If your coil is only a few weeks old, maybe take it back and exchange it (from other posts on the forum, there seems to be bad coils out there). It shouldn't be that sensitive to the battery being run down or we wouldn't be able to start our Jeeps up here in the cold weather.

Do you still have the old coil? Could swap that back in. Also, see if it starts if you spray some ether into the air intake hose. You were still thinking about a fuel issue a few posts ago. If it doesn't run on ether, you've probably got a spark problem for sure.

DFlintstone

87-90 Renix Jeeps need to crank 300 RPM for about two revs before it will fire. 300 isn't that fast though. I've had mine start when it seemed pretty slow.