Alright, getting ready to go turbo, so I switched from running fuel only (running off coil negative, using the '73 dizzy with a pertronix ignitor) to controlling spark with an 82 zx n/a vr dizzy. Now I've got a real strange spark problem. Spark to cylinders 2, 3, 4, and 6 is totally steady and fine. But spark to 1 and 5 is doing some pretty crazy things. Cylinder 1 doesn't get spark when the engine is accelerating. When the rpm's are steady (idle, or being held at any rpm), it's alright, but when I give it some gas, the timing light totally goes out, no flashes at all. Spark to cylinder 5 is just dead inconsistant. It'll be fine for a few seconds, then nothing for a few seconds, then a spark here and there, etc.
I have run spark control through megasquirt before without a problem using the '73 dizzy with the ignitor, I just didn't like to use it 'cause I would get tach spikes. I'm not getting any spikes or abnormal tach readings with the vr dizzy, so as far as I can tell, megasquirt is doing it's job without a problem. Regardless, megasquirt doesn't even know which cylinder is which, so it couldn't be picking out 1 and 5 for any reason.
The rotor and cap are new, but it does the exact same thing with the old rotor and cap. Spark plugs and spark plug wires are fine, and are the same ones I was using the same day with the other distributor.
I took some video (crappy quality, it's just my digital camera) of the problems. The frame rate is not fast enough to catch every flash from the timing light, but you can see when it's flashing and when it's not.
Timing light reading cylinder 1:
Timing light reading cylinder 5:
From my understanding of this, I don't see how it could not be a mechanical problem with the distributor somehow, though I don't know what that would be.
Any ideas?