Originally Posted by 6shutr
Faulty ignitor (or whatever they call it) could certainly cause a cutting out prob, but I've never heard of one cutting out just two cylinders only under certain conditions. So please let is know if that solves the problem. Also, i believe the N/As still used vacuum advance in the dizzy (didn't they?) It is common for the roller-ball assembly under the breaker plate to either lose balls or for the grease to just petrify after 30-some years and cause the advance to stop working. You can test this easily with a timing light on the marks and blip the engine - marks should move. (Can also test with cap off and sucking on vacuum line with your mouth - breaker plate should move easily.) If no movement, you need to disassemble the dizzy, clean up the mechanism, re-grease and put back together. This happened with a '76 I used to have and when rebuilt, the difference in increased power was really amazing.
Replacing the ICM fixed my issue. I am over the moon excited. So much work to this point. The very next day, I took it to emissions and passed. Plates on the way!
1983 Datsun 280zx Non-Turbo