So of course two days before I was going to get the car registered (finally), it's got problems again. Here's the rundown:

Very erratic failure of either (or both) of the leading plugs. Often one rotor doesn't fire at all making the car run like crap or just strait up die.
Sometimes trailing dies but this is less common.

I have so far checked the following:

• Plug wires - newish NGK wires, all within spec resistance
• Distributor (cap and rotor) - also almost brand new and low signs of wear
• Connections on the ignition box (for lack of a better name) - connections cleaned and grounds verified
• Coils - swapped leading and trailing, no change
• Igniters (j-105's) - cleaned, remounted, swapped position; no change

So, I'm staring to run out of ideas. Are there any other things that should be checked? I haven't found a way to test the igniters without a bit of equipment, but I seriously doubt both would go bad at the same time. The problem is most definitely spark (checked with a inductive timing gun) so rule out any fuel issues or things like that.

Any and all help appreciated,
Ben

1980 GS

 

Well I may have found the issue, but please correct me if I'm totally off - I don't know much about these cars ignition systems or what lies within the "box".

Incoming thought process...
By looking at my FB dizzy I saw the igniters we're mounted on it rather than the box, therefore the wiring instead went from the exterior pins to the box as opposed to the interior block pins running into the box and then to the dizzy like on the '80. Again, correct me if I'm wrong but I figured that the harness with that odd rubber shroud with the block connector ran from the pick-ups on the dizzy, through the box and into the back of the igniters. I tested continuity between pins on the block connector and those white plugs on the back of the box and one pin on the leading igniter has a broken circuit. In the photo it's the right prong of the left white connector on the box. All the others run through to the harness. Should I open the box up and see if I can find the break or is there anything to mess up by doing so?

 

Here's the photo:

 

I would test the igniters before you go any further.
The 1980 ignition was a little different from both earlier points and later electronic ignitions.
If you have the haynes manual, it says"To check the operation of the igniter, disconnect the two electrical couplers leading away from the box, but do not disconnect the wires leading from the box to the distributor. Using an ohmmeter, check for continuity between the two disconnected couplers. With the probes attached one way, there will be no continuity. Testing the other terminals should give a reading of less than 1000 ohms. If there is no reading at all, or more than 1000 ohms, the igniter should be replaced."

 

Well thank you for that information, I have read many parts of the Haynes manual but never that one. Good for future trouble-shooting . Anyways, I have since fixed the problem: People say check the basics first; well I thought I had but maybe I did one plug twice. Anyhow, the issue was a fouled spark plug that was shorting to the inner insulator. I actually did end up taking the box apart and was surprised how much there was (I'll throw a picture up just for kicks). I tested continuity and resistance a few places a figured out that the reason the one doesn't have continuity while off is that it runs through an IC of some sort, while the other igniter runs in parallel with one allowing continuity while not running. I also cleaned literally everything in the system, continuity checked every wire I could, and replaced the condenser - or capacitor - with one from an extra and previously operational dizzy. For the time being I have put the bad plug in the front trailing spot since trailing isn't really needed to run and it's also easy to get to when I replace it in a day or so.

Thanks again, and just another example of why you check the all basics TWICE, and then move on.