How do you test the fuel pump on a 1994 s-10 pickup?

Unfortunately that system doesn't have a test port so you have to tap into the fuel line at the fuel filter in order to install a fuel pressure gauge. It will require adapters, hoses and the fuel pressure gauge. Once you have a gauge installed, with engine off, you cycle the ignition key on and off several times until the pressure has peaked, it should read between 41 to 47 psi.