GS - 2nd Gen (1998-2005) Discussion about the second generation GS300, GS400 and GS430 (1998 - 2005)

Fuel Pump

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Old 05-13-08, 09:41 AM
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dmsrated
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Default Fuel Pump

Hello All,

I havent driven my car in a week and miss driving it very much. SO please help. I need to replace my fuel pump, and since Im broke, Ill have to have one my friends whose somewhat of a mechanic help. So does any one know how to or know the procedures to replace a fuel pump, like release the fuel pressure first and where to do that from .......Will I have to take the whole fuel tank out and stuff? I have the new fuel pump and filter coming so hopefully I can do it soon. To figure it out it was the fuel pump issue, he sprayed gas into where the Intake goes into after I started my car. The car kept running until he stopped sparying. Is his hypothisis correct?

Thanks

Last edited by dmsrated; 05-13-08 at 09:41 AM. Reason: misspell
Old 05-13-08, 11:49 AM
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KiPod
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I would check the harness where it connects to the fuel pump for signal first. I had the same problem on a diferent car before. My fuel pump wasnt getting a signal because there was a loose connection at a harness by the cars ecu. I had to trace the harness from the pump back through the entire car to find the problem though. But its better than throwing a pump in there to have the same problem.
Old 05-13-08, 01:11 PM
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macd7919
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Replacing the pump is a breeze.

1. Disconnect car battery

2. Release pressure from lines by slightly opening feed line to fuel rail OR you can disconnect the fuel pump harness at the top of the pump assembly (as discussed later) and then crank the motor over to clear the pressure (then unplug battery).

3. Remove the lower portion of the back seat.

4. Remove the three 10mm nuts holding down the fuel tank access cover located on the drivers side (Can't miss it)

5. Unplug harness and disconnect rubber fuel lines connected to top of fuel pump assembly.

6. Remove (careful not to drop them) the multiple bolts located around the perimeter of the assembly.

*Good idea to have a large rag handy from this point out*

7. Gently lift the whole assembly up (being careful of the fuel float arm, don't want to bend it) and remove the rubber hose going to the pump. This is where you want to have a rag handy to catch any dripping fuel.

8. You will need to rotate the pump assembly around a little bit to get it out of the hole with the float arm but it will come out.

9. Find a clean workspace to swap everything over. Reinstall in reverse order.

Good Luck!
Old 05-13-08, 03:11 PM
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dmsrated
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Good Lookin out MacD. I assume the fuel rail is on the engine and is there any sound it makes when you release the pressure. And how do you take the back bottom seat out, Just pull it or?
Old 05-13-08, 09:12 PM
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dmsrated
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Well I got the back seat takin out....To release the pressure, do you just loosen the nuts which connect to the fuel rail?
Old 05-13-08, 09:40 PM
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Spyder78
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in order to replace fuel pump the only thing you need to touch is the fuel pump in the rear. You do not need to do anything else. According to the tech manual you need to disconnect the harness plugged into the top of the fuel pump while the engine is running and wait until it dies. But I have done it without doing that only thing is that there a little fuel will spill as soon as you release the 8 bolts around the perimeter of the fuel pump you should have no problems with continuing.
Old 05-13-08, 10:27 PM
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FrankT
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Your diagnosis sound incomplete to me. That is half the work...

Your friend sprayed fuel in the intake and the car ran when started until the fuel stopped.
This definitely leads to a fuel problem.
BUT if the injectors were not operating replacing the fuel pump would do no good.
I would first verify fuel pressure in the fuel rail...by disconnecting the fuel line and see if there is fuel under pressure.
If there is no pressure try starting the car with the line disconnected and be prepared for fuel to spray out, use common sense.
This will verify your fuel pump operation.

Good luck
Old 05-14-08, 06:54 AM
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Is there any way to tell the fuel pump is bad once it has been taken out, from looking at it?
Old 05-14-08, 08:48 AM
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FrankT
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Originally Posted by dmsrated
Is there any way to tell the fuel pump is bad once it has been taken out, from looking at it?
Hook it up to 12 volts with a ground for just a few seconds and listen for a nice constant spin.
Old 05-14-08, 10:46 AM
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The possibility of all your injectors going bad at one time is almost 0. As mentioned you can test the pump by hooking up a battery to it's power terminals, I would recommend a drill battery.
Old 05-14-08, 11:47 AM
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So once I replace my fuel pump, my car should start right away smoothly? taken if the fuel pump was the issue.
Old 05-14-08, 02:13 PM
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If the pump was the issue it should start fine. At first its going to take a little bit to build pressure back in the lines so you may have to crank it for awhile but once it starts it should start normally after that.
Old 05-14-08, 04:26 PM
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If I have a half tank of gas, will that matter when I change the fuel pump.
Old 05-14-08, 04:53 PM
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Is there an easy way to remove the rubber hose on top of the assembly. Crap its pain in the a$$.
Old 05-14-08, 05:59 PM
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well the fuel pump has been installed but still havent started the car yet, worried if the old fuel mess anything up. Now thats installed, anyone know where the fuel filter is. Want to replace that too before I get the car running.


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