The symptoms are not constant making this very difficult to diagnose. It started over 6 months after my coil blew melting my dist cap. After replacing the cap, rotor and coil the car ran fine for months. Then developed a slight power loss hiccup when accelerating from a stop on a hill (it was worse when turning left) that progressed to shutting off completely and randomly, sometimes starting again right away when parked and sometimes popping the clutch when moving. When it won't start it cranks healthily, is getting fuel but signal at the distributor is inconsistant or weak at times.
I checked the wiring, working back to the fuse box as best I could then from ignition to fuse box. After I did that the car cranked up unsteadily at first then normal sweet sewing machine sound. I figured faulty wiring/ignition and sure enough wiggled a wire cluster and killed the car, wiggled it again and it cranked. So I pulled the fuse box and cleaned all the contacts. It ran great on test drives but after driving to work the next day it will not crank.

I have checked fuses, replaced the coil, cap, rotor and main relay. The comp gives me the all clear wink.

 

Sounds like you have a broken wire in that harness you shook. Pull back the harness wrap and check for breaks. Also check and clean all grounds.