AND NOW yet another annoying story from the old days.
In the early 70's, in the Navy, had a part time job at the NAS Miramar auto hobby shop. Couple of guys brought in a late 60's Ford they'd tuned up, into the "tune up bay" and it would barely run and move. They had worked on the thing off base somewhere, I have no idea how they managed to get it there.
I SWEAR TO GOD this is the truth best of my memory.
First, they had replaced the plug wires and put them in place THE WRONG ROTATION. This means the engine was only firing on 2 cylinders, and cross firing on "some" others.
After getting it on the Allen machine, here's the rest of what I found
The points, with no lube at all on the rubbing block, were gapped almost closed, and opening purely by luck. It just might be they were not in fact opening on every cylinder.
The vacuum advance can was ruptured, so no vacuum advance
There was no functioning mechanical advance, because at some point someone had dropped a screw inside. This means, they now need a rebuilt distributor, because the advance mechanism was damaged..
So plug wires wrong rotation, points almost not opening, no vacuum nor no mechanical advance. This was the early 70's and I can still remember that.