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2003 fuel pump electrical test


jeffg095
07-04-2006, 08:38 PM
My 2003 Alero V6 automatic 57000 miles died yesterday at a busy intersection (of course) and won't start. Towed it home, and found absolutely no pressure at the rail and the fuel pump does not run when you turn the ignition on. Checked fuses and fuel pump relay, all are good.

Before I spend the big $$ on a new fuel pump and drop the tank, I want to be sure that the electrical connection at the tank is good. I believe I have found the fuel tank wiring harness here:
http://i78.photobucket.com/albums/j109/jeffg095/2003_Alero_fuel_pump_harness.jpg

There are seven wires in this harness. Which one should be hot for the 2 seconds or so when the ignition is turned on? Is there anything else I could/should test for with this harness? Any words of wisdom from someone who has already done this would be greatly appreciated.

Thanks, Jeff

jeffg095
07-05-2006, 11:12 PM
It was the fuel pump, changed it out and I'm back in business. Jeff

nqc2k
07-06-2006, 03:37 PM
did u do it urself? Mine doesn't start like it should so im thinkin it could be a pump goin......but i looks tough to drop the tank and replace.....how hard was it?

jeffg095
07-06-2006, 05:01 PM
did u do it urself? Mine doesn't start like it should so im thinkin it could be a pump goin......but i looks tough to drop the tank and replace.....how hard was it?

It wasn't too bad, took me maybe three hours. If you haven't yet, get your head as close to the tank as you can under the car and listen while someone else turns the ignition on (but don't crank it). If you hear a buzzing noise for a few seconds, your pump is working.

The first thing I would recommend is that you get the Haynes manual at Auto Zone, the money you save by doing this one job yourself will more than make up for the cost of the book, and you'll have it for other repairs in the future. Get a fuel filter while you are there, you'll want to replace it as well.

If you have theftlock on your radio, make sure you disable it before you disconnect your battery, or your radio could be locked when you reconnect it. See other posts in this forum to read about that.

Open your gas cap to relieve any pressure in the tank. Find the schrader valve (looks like a tire valve) on the fuel rail line on the engine. You want to let the pressure out, so you can either use a tool to bleed the gas or just have a can/rag handy to catch what might come out. Since my pump was not working, I had no pressure at the rail at all.

The hardest part was siphoning the gas out of the tank before I started. Unfortunately I had just filled it up the day before, so I had a lot to get out. After you jack up the car and have it on stands, there is a short piece of flexible hose that connects the tank to the fuel filler pipe. Disconnect this from the tank, and snake in your siphoning tube right at the tank (you'll never get the siphoning hose all the way in if you start on the outside of the car where you fill it). My tank had some type of mechanism that partially blocked the inlet opening, and I had to wiggle the hose around to find an opening to get it in. I was using 3/8" tubing, I couldn't get anything bigger than that into the tank.

Remove the exhaust heat shield. Haynes says to lower the exhaust system and rest it on the rear suspension, but I didn't have to do that.

Take a look at your replacement pump to see how the plastic fuel line clips work. You need to unclip it and squeeze the ends together in order for it to push "up" and away from the fuel line.

Disconnect the wiring harness. Disconnect the EVAP hose from the canister. You may need a small screwdriver to get the plastic flaps over the lip. You'll see what I mean when you do it. Disconnect the fuel feed and return lines (these had green and blue clips on mine). You'll need some shop rags to catch the gas that will come out of the lines.

Loosen the fuel tank strap bolts. If you are by yourself, have a floor jack or some blocks of wood so that the tank cannot fall to the ground. If you have a helper they can help manuever it. Lower the straps and wiggle the tank down and out. I had to move mine towards the passenger side to get it over the exhaust pipe.

Once you have the tank out, it will be straightforward how to take the old pump out and put the new one in. While you have the tank out, replace the fuel filter. You'll need two wrenches, one to hold the nut on the fuel line and the other to turn the nut on the filter.

Everything goes in the reverse of how it came out. Good luck!

maxwedge
07-06-2006, 06:58 PM
did u do it urself? Mine doesn't start like it should so im thinkin it could be a pump goin......but i looks tough to drop the tank and replace.....how hard was it?
First things first, get a fuel pressure gage on it and see if it is bad.

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