I have a 92 Mark III conversion. 5.0L 155k miles.. Everything was fine until I decided to clean it and wash it up for my wife..(scared it to be clean I think)..but anyway the fuel pump is running constantly once the key is turned on..used to just run for a few seconds then shut off. tried to start it up but it wouldn't start??..pulled engine cover and i have spark, and seperated fuel lines at the engine and i have fuel coming up and fuel returning. I turned the distributor clockwise looking at it and got it to start but is blowing black smoke and what seems to be raw fuel out the pipe,and not enuf power to move it. I capped the return line with my thumb to see if the pump would stop after building pressure but it keep running.
Any help?? ideas??..timing chain maybe?...

 

The fuel pump relay might be stuck. It's in that black fuse box under the hood on the drivers side. On my 92 there's three relays in there, the middle one "H" is the fuel pump relay. Turn the key on and give the relay a few taps with the handle of a screwdriver and see if the pump goes off.
Also, It's along shot, but pop the cover off the code test connector and see if you got water in it.