Fuel Pump Pressure ?

1993 GMC Truck C1500 1/2ton P/U 2WD 5.7L TBI 8cyl........ . I know it should be 9-13, it test at 13 but drops to 0 when pump sound stops,I start engine and it 's back up. No sign of leaks. Engine cut out on me and it seemed like a fuel problem. It did not want to restart till it cooled down.

1st thing to do when this happens is check for spark if ok see if the injectors are spraying.

The small positive wire from battery has melted to exhaust manifold. I thinking this maybe the problem.