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Which fuel sending unit is acting up?

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Old 03-26-2009, 07:10 AM
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Which fuel sending unit is acting up?

I've just got a quick question. I've searched but can find out how the dual fuel sending unit system works. Does one read high and the other low fuel levels, or are they averaged? The reason I ask is that on my 04 the fuel gauge stops reading at just below half a tank. It stops there and stays no matter how low the fuel level gets up to the point where I run out of gas. (Found out the hard way) Above that level it reads just fine (ie. from full all the way down to where it stops moving) I am trying to figure out where to start troubleshooting, but I don't know which side (driver or passenger) to pull first, or if I need to pull them both.

Last edited by Paradox_Racing; 03-26-2009 at 07:33 AM.
Old 03-28-2009, 09:44 AM
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Nobody??
Old 03-28-2009, 09:49 AM
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Correction - I was talking about something else.

Last edited by nycgps; 03-28-2009 at 11:37 PM.
Old 03-28-2009, 07:55 PM
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They are both averaged I think...you will likely find that one is stuck up

Best to pull them both and check. You want to have minimal fuel in the tank......about 1/8th ank or less so you don't have to play in all the gas
Old 03-28-2009, 11:20 PM
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Originally Posted by nycgps
replace ur fuel pump

the level sensor is on the pump itself
nope.

beers
Old 03-28-2009, 11:21 PM
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^ I quit arguing a long time ago
Old 03-28-2009, 11:27 PM
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Originally Posted by swoope
nope.

beers
hmm?

One of them is not working. So yeah, replace it? wrong ?
Old 03-28-2009, 11:35 PM
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I think he was pointing out that the sensor isn't on the pump
Old 03-28-2009, 11:36 PM
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Originally Posted by dannobre
I think he was pointing out that the sensor isn't on the pump
hmm ... ok
Old 03-28-2009, 11:55 PM
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Originally Posted by dannobre
I think he was pointing out that the sensor isn't on the pump
yep.

and note. if you dont connect the plug on the exhaust side of the tank. you get no fuel reading.


dee, dee, dee.

my observations. you have two fuel sensors. they are both inboard. tucked next to the hump in the tank.. i would guess that dan has it right. they average..

beers
Old 03-29-2009, 10:25 AM
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Thanks for the replies. I wasn't planning on just replacing parts blindly, but I don't have the tool, so I didn't want to spend all day trying to get one ring off just to find out it was the other. Hopefully it's just stuck up, but I'll test them both. Thanks again! Oh, and BTW you can order the sensors separate from the fuel pump. They both have their own part numbers.

Last edited by Paradox_Racing; 03-29-2009 at 10:28 AM.
Old 03-29-2009, 11:37 PM
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When the tank is below 1/4 the fuel will be all in the drivers half of the tank in normal street driving. You can check the level sensor resistances from the pin outs on the top of the pump on one side..and the cover on the other. You should be able to tell what is happening if you add fuel...

Problem is...once the tank is filled..you will know which one isn't working....but you also will need to empty out the tank again to fix it
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