CJ Ignition Problem, please help!

[jay79cj7]

I took today off work to finally do the herculiner on my CJ. I went to pull it out of the garage to hose it off, and it won't start. It turns over, but doesn't fire. I just got the thing running 2 weeks ago after a total rebuild, but have not had any problems in the short trips I have driven it on and the dozens of start ups.

Its getting air and fuel, no spark. I took a spark plug, held it to ground, and watched for spark as I turned it over. No spark.
I checked all the obvious electrical connections and all seem ok.
The coil is getting power in the start and run position.
I swapped the TFI coil with the old stock coil with no luck: not the coil.
I figured it must be the ignition module. Took it to autozone, had it tested, and it failed "5 out of 6" tests the guy said. Traded $20 for a new one. Still doesn't work.
Pulled out the Haynes, read through it, and decided to check the pickup coil resistance. Its good.

Background on this Jeep: I did a TFI upgrade a year or 2 ago and it has worked fine. I put in a "painless" wiring harness during the rebuild, and now I have a ballast resistor that they provided, which is different from stock. It worked fine for 2 weeks, and there is nothing wrong with it now, I checked.

I cannot figure this out at all. I am stumped and very frustrated that my vacation day is going to waste. Any advice out there?
Thanks in advance.

 

[jay79cj7]

RE: full of dumb questions today...

Where's the help? :wink:
I got it going a few hours after posting. I gave up, went inside and watched the Cubs give up, and then tried again.
I had left the ignition in the on position on accident, and the TFI coil and ballast resistor were nice and warm. Great. The ballast was burned out. I put a jumper across the ballast, put the old stock coil back in and it started up. Switched back to the TFI, nothing. I guess the TFI is bad too.
I have a ballast bypass on start, so I know the ballast wasn't keeping it from firing, even if it was by chance bad all along. The ignition module tested bad, so that was definitely part of the problem. Now the coil seems to be bad, although that may have just been from me leaving the ignition on for 2 hours.
I don't understand why it runs now because I am 99% sure that I tried the old coil with the new ignition module and it didn't work before giving up and watching the Cubs. I am quite confused, and kind of worried I am going to get stranded somewhere.
How could the coil and module work fine last time I drove it, and then both magically die while sitting in the garage?
Anybody know a coil (that doesn't cost a ton) that can take a full 12V or at least won't be as sensitive to higher voltage? It doesn't run as good with the stock coil.

 

[GaryMB]

RE: waterlocked

I bet an msd coil would withstand 12v better, but don't know if it would be damaged or not. An msd tfi or external hei coil shoud cost around $40. I'm guessing the 1979 cj's ignition is not hooked up to a computer, so that eliminates one possible failure. If the ignition module and coil are good, I would check the distributor.