You said your truck fuel pump runs all the time with the key on. Is it a truck or a ford explorer. Two different things. Ford explorer fuel pump relay is grounded by the PCM. Maybe you need to check to see if you also have spark at the spark plugs. If not you need a test light or noid to check the injector circuit to see if it operation. With a test light test check one of the injector plugs for a completed circuit.
Take the test light put one end in one side of the plug and the other in the other side. Have someone turn the engine for you and see if the light flashes If no spark and no circuit at injectors and pump running all the time. I would expect your PCM is Bad.
Wednesday, August 27th, 2008 AT 8:53 PM