[old_master]

Make sure the fuel filter is not restricted. You still need at least one more piece of data to complete your diagnosis. Key on, engine off, fuel pump running shows 60psi, which is at the bottom of the spec. After the fuel pump shuts off, pressure must remain above 55psi for 3 to 5 minutes. If the pressure holds, the pump is faulty, (unable to build sufficient pressure). If pressure does not hold, it could be either the check valve in the pump is leaking, fuel pressure regulator is leaking, or lines under the plenum are leaking. Post your results and we'll continue, if necessary.

GM does not publish any "engine running" pressure specs, all pressure tests are done with the engine cold and off.