Try a different dizzy, you said the rotor moved and had some play, that should be tight on the dizzy shaft, your bearing in the dizzy may be going allowing that to move around. I know my ed civic has the same problem, when it was cold it would work ok but then when hot it was junk and barly ran and missing and all that great stuff. Also over 3500 rpm it would break up real bad. Take dizzy off and move the shaft around and turn it. You will know if the bearings going.

When it can move around, the rotor doesnt come close enough to the cap terminals so it misses spark that rotation causing all the problems

 

oh shit, I bet this is whats fucking up my sol once it warms up!

wish I could rep you more

 

Does this happen both with and without the cars heat on? Check the dizzy first but if you are getting wierd things happening as the cabin warms up, check the main relay solder joints.

If you need a cheap OBD0 MPFI dizzy pm me. I have one sitting next to my desk that seems to be in good shape, no shaft play, and all components are there but I have no way to test it.

 

It happens irrespective of the cabin temperature. It seems to be pretty much whenever it's at operating temperature. I'll PM you.

Another thing... I was just looking over the engine compartment, and found this little guy unplugged, sticking out of the wiring harness above the starter. The thing is, I have no clue what it goes to. Here's a picture:

There's also another large plug in that area that doesn't seem to go to anything, but I didn't think to take a picture. I will when I get a chance though!

 

That picture is a bit fuzzy, but I believe that is the water temp sensor. It goes in the head right in that area, kinda under the dizzy and above the starter.

 

The loose wire is most likely the original starter signal (black with white stipe?). I can see the signal wire on the starter is an add on someone did at some point.

A bad bearing in the distributor allowing the shaft to flop around isn't doing you any favors.

 

It's a wire with a yellow bit of tape on it and a kind of crimp connector dealy. Looks like it would slide on to a tab of some sort.

Would a bad bearing in the distributor cause sometimes violent misfires? I mean, it really bucks around. It idles kind of rough when this is going on but removing the plug wires on any one cylinder makes it run even worse. I'm scratchin' my head, I tell ya.

 

Bad bearing in the dizzy can ruin your life hardcore. First off the tolerences in there are pretty tight so it wont take much wobble before you are hitting one magnetic pickup an getting too far away from others, which can mess with the electronics pretty bad. However the real dozy is that the dizzy is driven off the cam which is driven off the timing belt, so as that bearing goes out and the shaft gets more play it will grind harder against the magnetic pickups eventually causing your timing belt to break or jump teeth which will cause your pistons to meet your valves in an highly unpleasant way and completely ruin the motor.

For the wire look for a sensor with a single metal post kinda under the dizzy area.

 

Replaced the dizzy, seems to be doing better. I'll reserve judgement til it goes a few days without messing up.

The old distributor bearings were just about shot. Each turn of the shaft was punctuated with a 'snick-snick' type feel and sound.

I'll update in a few days if all is well. Thanks guys!

 

UPDATE: After one day, the misfiring and O2 CEL came back (this is a brand new NTK O2 sensor, not the crummy bosch one). Any other ideas? Should I rewire the O2 straight to the ECU?

The car doesn't smoke/burn oil/burn coolant, doesn't leak around the head gasket or valve cover gasket, and doesn't have oil/coolant contamination. The oil does smell like gas a little though.

*EDIT* And just for it to be known, if I turn the car off and back on, sometimes the problem doesn't come back for that drive, and sometimes it comes back within a few minutes.