Expert: autohelp - 9/26/2009

Question
there's no power getting to my fuel pump after i put a meter to the grey wire and ha my son to turn the car to on position. nothing. could it be my the factory security system? the engine turns over but doesn't catch. thank you for your help.

Answer
When you first turn ON the ignition switch the computer sends a 2 second battery voltage signal thru the fuel pump relay to the fuel pump to prime the fuel system so the vehicle ill start easily.

Once the engine is running the computer by-passes the fuel pump relay and sends a constant battery voltage signal to the fuel pump at all times as long as the engine is running.

Perform this test:

1. Remove the gas cap.

2. Listening very carefully with your head out the door and getting as close to the ground and listening at the gas tank.

3. Turn the ignition switch to the ON position ONLY, Do NOT try and start the engine. You should be able to hear the electric fuel pump motor run for only 2 seconds and then it will stop.

4. If you can hear it run for the 2 seconds and then stop, You do NOT have a fuel pump problem.

   (a) If you do NOT hear the fuel pump run for the 2 seconds and stop then the fuel pump is faulty and requires replacement.

5. If the fuel pump is OK, You need to check for spark to the spark plugs.