I have a 78 that I've had a lot of problems with in the last couple months.  I'm going to list all the problems in case they are related.
The engine seemed to run hot, and after driving for a while, if you shut it down and didn't wait for it to cool down, it would start back up but would die within a minute and then it wouldn't start again until it sat for an hour or so.  When this happened I would get no fuel to the carb.  I couldn't get a mechanical pump right away so I threw in an electric pump that had similar specs to the factory pump.
 After changing the pump, I drove the car for a while, let is sit for about 10 minutes, tried to restart it and it wouldn't. Ran the battery down trying to start it.  Couple hours later, jump started it, drove home with no trouble.  Next time I went to drive it, battery was dead.  Put a new battery in, drove it about a half hour no problems. Couple hours later, drove home, again, no problem.
  Sat for two weeks, was really hard to start and when it finally did start, it wouldn't accelerate.
So, I replaced distributor cap, rotor, plugs, plug wires, timing belt and rebuilt the carb.  It stars very easily, but still doesn't accelerate.  I wanted to see if the advance was working and tried to rev it while using the timing light and noticed that when I tried to rev the engine, the light would go off, then come back on after I backed out of the throttle.
   Is this an ignition module issue?  coil?  distributor? something else entirely?