It was a shot fuel pressure regulator!
Used one was FAILING.
Swapped it out with another used one from the wrecker which turned out to be a TOTALLY FAILED unit!
Engine surged terribly and fuel was pulsing from the FPR thru' the vent hose to the valve cover breather in rhythm to the surging of the engine!
On my FAILING FPR, a VERY SLIGHT amount of fuel leaked but on the TOTALLY FAILED one, it was very obvious - it wasn't leaking fuel but it was venting fuel!
Cheers, y'all and thanks for your ideas.
I have posted my FPR findings in another thread and hope it helps others diagnose similar problems in their cars.