Faulty fuel sender unit??

[98 OB RNV]

I picked up a 97 Outback in San Diego and drove it back to Reno. My wife drove our 98 Outback (both autos). Each time we would fill up (on my request) I would have close to a quarter tank less than her and drive the same distance and small amount of difference on fill up gallons. It was seeming like I was getting 150 miles per tank:spin:. Faulty fuel sender unit or...????

[Stang70Fastback]

Possible. The Legacy has TWO fuel senders - one on each side of the tank - because the tank is a saddle style. If either one of them goes back you will notice the gauge dropping a lot more quickly than it should.

[boattlebot]

any way to tell if somethings up wit the fuel gauge? im just wonderin cus i never saw the fuel gauge new, i bought it super super used and wouldent be suprised if it was wonky

[spooln30]

^ I don't really understand your last comment about seeing the fuel gauge new? In most cases the sender is what fails I have never replaced a fuel gauge on a second gen.

[Stang70Fastback]

Not sure how to test the fuel gauge directly, but as I understand it, issues with the fuel gauge are generally a result of a bad sender, not a bad gauge.

[98 OB RNV]

From what I can tell looking at the FSM manual is,

Fuel meter unit is built in fuel pump assembly.

and a fuel sub meter unit...

 

The fuel pump was replaced, not by me.

[Stang70Fastback]

Its a very easy item to replace. I'm assuming it's a wagon since you said it's an Outback. All you need to do to get to the fuel sender is remove the floor in the trunk (very easy) and then flip up the sound deadening and you will have access ports on each side of the wagon. Unbolt those and you can get to the tank, where you can get to each of the fuel senders - and yes on the passenger side, the fuel sender is part of an assembly which includes the fuel pump. It's all very straightforward... just stinky.

[98 OB RNV]

Any idea on the parts cost?

[johnegg]

put some ''techron'' fuel system cleaner in the tank.

that may help.

 

if i under stand your original post,

you drove both cars the same distance

and filled them at the same time,

but the 97 gauge showed empty and the 98 showed ~1/4 tank.

that's the fuel sender.

 

most folks just reset the trip meter at fill up and buy gas when they hit a certain mileage point.

 

but the tank holds 15.9 gal. (20 L).

if it reads empty and you fill up with 10 -12 gal.

then you have 4- 6 gal left in the tank.

 

in most cases, the low fuel light will come on with about 13 - 14 gal gone.

it is a separate device and they rarely fail.