EEC Power Relay/Shutdown problem

[Lashbrook27]

I have a 1990 Mustang Gt. A couple of days ago I started my car up and about 30 seconds to a minute later it started to die. When it did I noticed the fuel pump relay under the seat started open and closing really fast. A relay located near the intake tube was doing the same thing. It did this a couple of times after starting then worked and I was able to drive home. I haven't been able to find the EEC Power Relay, but the other two relays are good. Could it be that the EEC Power relay is going bad, or maybe the computer is acting up? Where is this EEC Power relay located? This initial prime for the fuel system is good. The fuel pressure gauge hits 42 psi, but I am assuming that is because the pump is going off and on while the engine dies.

...1990 Mustang GT-Stock block and cam/GT40P Heads/Ford racing headers/BBK High Flow H-pipe/40 Series Flowmasters dumped/Cobra intake/24 pound injectorss/73 c&l MAF/Automatic trans w/shift kit & tranny cooler/MSD cap & rotor/MSG 8mm wires.......

[Lashbrook27]

I found the EEC Power relay above the computer. I jumped the power to find out the circuit before the computer is good. I ran it for a couple of minutes and it did the same thing. The fuel pump relay strated opening and closing really fast and the engine died. Is the computer cutting it off and on like it is doing the initial prime? Anybody know what is going on here?