Howdy,
I've got an 81 so shouldn't be too far off on this.  Things to check:

KEY OFF CHECKS
+ ground connects at rear of the engine, shiny and tight?
+ check little clips in connector to AFC, all there and not pushed in?
+ big connector to the ECU at left side of engine, remove carefully, check
  that all clips are intact.  Engage several times to ensure that no 
  corrosion between clips.

KEY ON, ENGINE RUNNING CHECKS
+ move all engine wiring, keep hands, hair, away from moving parts.  You're
  checking for broken wires, shorts, etc.
+ move wiring to starter, same as above.
+ check connectors, wiring, to head temp sensor.

That's all that I can think of right now (2:30 am, no sleepy), write back 
in the morning with any questions.

Jack