Ok so I bought an 87 RX as is not running, I was nearly positive the reason it wasn't running was ignition timing. So... I have re-timed everything to correct timing, I have fuel, I have spark, and I have great compression. It still won't run or even try to start. At this point I don't have a clue... I have tried everything I can imagine with no success. Can anyone offer some ideas of possible issues that be the culprit or culprits to my problem?

Have you checked all of your fuses or fusible links ? How about the starter ?

Yep all fuses and fuse links are good. It cranks great just not firing up.

My guess is timing. Distributor timing off/firing order wrong/cams off. 

I have checked and double checked all the timing. It isn't perfect, no way can I get it perfect without the engine running, but it's close enough that it should fire.

Have you had someone try turning the disty while you crank ?

Is the fuel pump working? Common problem on the earlier "black" ECUs for the earth side of the fuel pump circuit to fail. Attach the earth side of the fuel pump wiring directly to the body instead.

 

Also, is the wire from the negative side of the coil connected to the ECU? I had a conversion not run because I hadn't connected that wire... took me 6 months to find the problem

I have fuel pressure and I have spark but no I have not tried turning the distributor while cranking. I'm really thinking its a sensor of some sort but I have no idea what sensor would completely stop it from even trying to start.