It's not likely that your pickup is leaking. The pump should run from a can okay. Pumps left with old gas in them often tar up, but if it's whining, it's running. Click in the injectors are sometimes quiet. To test correctly, remove the fuel rail and nozzles and put them into cans. Crank the engine/turn the throttle switch to see if there's spray. White wiring to injectors is old and weak. Pay especial attention to that central grounding point on the intake manifold where they're all crimped together. Unfortunately, there is little slack, so repairing that, if there is a problem, is a bother.