If you're sure you have spark, that's a dandy clue that really limits the possibilities. Listen at the tank or filler tube when someone turns the ignition switch on. You should hear the pump run for only two seconds, then it will turn off until the engine is rotating, (cranking or running). If you don't hear the pump run, check for 12 volts on the dark green / white stripe wire for that two seconds. If it's there, the problem is in the connector, pump motor, wires, or ground.
If the 12 volts is missing, the wire is either open or grounded, or there's a problem with the fuel pump relay. You can jumper the contact terminals in the Power Distribution Center under the hood, or remove the relay's cover and squeeze the contact. If you hear a hiss from the fuel pressure regulator, the pump is running. Suspect a defective engine controller which runs the relay. (Remember, this assumes you have spark).
If the pump still doesn't run, measure for 12 volts in the relay socket. If it's there, but goes away when the circuit to the pump is connected, the wire or pump is grounded. Unplug the pump and try again. If the 12 volts still goes away when the relay is jumped, the wire is grounded. No fuse will blow; there is an electronic circuit protection device built in that will turn power back on the instant the short circuit is gone. If the relay doesn't turn on, it's rare for one to fail, but you can try swapping it with one of the other relays. If another relay doesn't work either, suspect the engine computer.
Sunday, April 12th, 2009 AT 5:45 AM