runs 5 seconds then dies

My 1976 265 has a B230 with lh 2.2 in it. It ran perfectly then I went outside and all of a sudden it ran for about 5 seconds and then just died. If I try to restart it the car will just keep cranking. No spuddering no attempt to start at all. I have bypassed the fuel relays and nothing. I can hear both pumps running and am confident that I have spark. Probably should double check. If I let the car sit for an hour or so it will start for 5 seconds again. If I unplug the maf and put it in limp it still cranks and dosen't attempt to start. Any ideas?

A) You could try Art's method of using a hose to see if in-tank pump is actually pumping fuel, or just running ? (submersible hose issue ?)

B) have you tried put a bit of fuel into intake to see if it fires up ?

Ideas!? Yes, do diag. Spark, fuel pulse, fuel pressure. Or blast brake cleaner down it's throat and see if it runs. Click my sig