The solenoid posts only get power when the key is in the start position. The one on the left gets 12 V when you turn the key to start and actually causes the main contacts of the solenoid (which passes the 12V from the battery connection on to the starter) to close. The terminal on the right is used to supply 12 V to the coil (instead of the normal 6V or so) during starting. The reason for the 12V is to give an extra kick for things like cold/damp start situations. If the car is cranking when you turn the key to start, your solenoid is probably good. And since the other circuit is just a boost for cold starts ( the 6V is there all the time, as long as the key is in on) that part shouldn't be causing your problem, but you can still check to see if the right hand post jumps to 12 V when you turn the key to start. When you say you checked the coil and it was "good", how did you check it? Have you pulled one plug wire and held it near a ground while cranking to see if you've got a good spark jumping? I would be tempted to say something in the dizzy (rotor /points/etc, but if you've swapped it with a known good one that kind of narrows that down. Not sure I've helped at all ..... don't you just love ignition problems. Good luck and keep us posted on your progress.
Rich
