'72 Duster starting And Running Problem

And then?
The suspense is killing me....
It Started to Sputter And Then Finally Stopped I've Replaced the Following: Distributor Cap And Rotor, Pickup Coil,(found this to be missing rivet at pivot point)Four Connection Rigistor,and Wires/Plugs Coil Is Okay Car Cranks Strong But Won't Continue To Run Wonder If I Missed A Step or Wired it back up Wrong ECU Has Four Pins