Fuel Gauge Sending Unit Replacement
 

Wondering if there's a gasket that I need to replace when pulling the fuel pump to replace the fuel gauge sending units. Couldn't tell on the "subaruparts.com" parts diagram. Anybody know and have a part #?

Re: Fuel Gauge Sending Unit Replacement
 

I don't believe so, even though the FSM refers to " always replacing" it. There is no gasket in the FSM diagram either. IIRC the rubber seal is the only thing keeping it air-tight, and may in fact be what they are referring to. The 3 tanks I've opened and closed were resealed successfully without replacement. Just my $.02.

Glenn

Re: Fuel Gauge Sending Unit Replacement
 

If you're successfull in changing the unit and finalising it all, I was wondering if you could do a How-To for this fix.

It's a fairly common fault that the gauge needle wonders all over the place during the times that the gauge actually works.

I depend on the Amber fuel light to come on to refuel. My gauge only works for a day or 2 after a refuel after that it's not accurate or drop's down slowly.

Is all the work done through the panel just aft of the rear seats?

Re: Fuel Gauge Sending Unit Replacement
 

AUSVX,
The process can be rather "painful" as one twists and turns the sender to attempt reinstallation unless one pays careful attention to how it came out. Yes, all is done through the panel you mention, after removing the cover of course! The easiest job I did was after using a little hand pump to empty the tank as much as possible, but the fumes can still get to you. Be certain to ventilate the work area fully.
AFTER RELIEVING FUEL PRESSURE (by disconnecting fuel pump electrical connector, starting the engine and running it until it stalls, then cranking an additional 5 sec, then OFF)
The FSM process is as follows:
1) Disconnect hoses and harness connector(done), and remove the fuel tank cap. (I've been successful removing the tank by placing a large screwdriver on one of the protrusions and lightly tapping with a dead blow hammer to unscrew it)
2) Remove bracket cover for installing each assembly bracket onto the tank inner. (This bracket clips down onto the mount to secure all pieces together and must be pried up at one edge to remove, straight up.)
3) Take out fuel meter unit LH (As you look at the tank)
4) Take out fuel meter unit RH.

As stated previously, be sure you observe the way the pieces come out so you may reinstall in exact reverse order.

I dismantled the senders from my '93 after her demise to figure out what was causing the flaky gauge operation. (aside from the saddle tank and jet-pump arrangement that always keeps fuel in the left side for the fuel pump. I used a multimeter to determine that one sender was erratic, showing resistance/open sporadically as I swung the float arm through it's arc. I dismantled the sender box to find the contact point was not making good connection. I installed a small washer on the shaft to force the contact against the rheostat and reassembled the box. Testing again I found it was now stable, and resistance changed in nice linear fashion as the float arm was moved. :)

Hope I haven't missed anything. Best of luck should you tackle this little job. :cool:

Glenn

Re: Fuel Gauge Sending Unit Replacement
 

Well, I replaced the sending units today, and the gauge reads perfectly! :D

Took me about 2.5 hours, working slow. I'd add a few things to Glenn's list.

1. I ran the tank down to less than 0.5 gal left, I think that made the fumes more tolerable.

2. The bracket spring-clip cover is best removed with a slot screwdriver by prying on the two tabs on the passenger side of the clip (LH side as you're working facing the back of the car). The two cover tabs have a slot that must be pried over the small protruding key in the center of each tab. Just pry up both sides and the whole spring-clip cover will come straight out.

3. Both sending units came out with a counterclockwise half-twist (180 deg rotation) as you wiggle them out. Went in with a clockwise half twist as well.

4. I had a heck of a time getting the connector on the LH sending unit installed. Had to partially pull the sending unit back out so I could get two hands on it for good alignment.

5. You need to put the tank cap back on without the plastic screw-on cover in place, so you can be sure the rubber "packing" gasket is fully seated into the tank and seals the opening. I bought a new packing, the old one looked fine, but was much "looser" around the cap from years of gas exposure. Anyway, put the cap back on with the packing seated properly, then put the plastic screw-on piece over the cap and screw it down. I screwed it down hand tight and then tapped it with my screwdriver and hammer about a fifth turn tighter. Then replace all your hoses, and button it up.

Overall, this is not that hard a job. Worse thing is the fumes, which aren't so bad if you get the tank really empty...

Re: Fuel Gauge Sending Unit Replacement
 

Hey thanks a lot for your effort in writing this up next time a get a break off work I'm going to rip into it.

Thanks, Jordan.

Re: Fuel Gauge Sending Unit Replacement
 

Ran a tank of gas thru the SVX after fixing the fuel gauge sending units. This car actually has a very good gauge! It is very linear. 14.2 gallons from full (1 needle width above the full line), to the "empty" fuel line. That leaves 4.3 gal in the tank. That's just about the way you'd want it to be...

Re: Fuel Gauge Sending Unit Replacement
 

AMAZING car isn't it?!! Enjoy !!!

Glenn :cool: