fuel guage....

subymtnguy · #1 06-04-2002, 07:17 AM

Still waiting for my FSM's from subaruparts.com that I ordered on May 9th....so in the meantime I hope you guys can help me....

The fuel guage on my 92 LSL really pisses me off....It has never worked since I got the car. When I fill up it may show to 3/4 full for a few miles and then fall to the big "E" for a day or so, only to come back up to 1/4 full....bottom line: It reads all over the map when it works at all!....most of the time showing empty....

Anyone else have (had) this problem??

All ideas appreciated...just trying to get things right for the 10th ann. meet....

Beav; can you help?...

Thanks gang....

vkykam · #2 06-04-2002, 07:56 AM

Let me know what your results are. Those are my problems to a tee.

I also have excessive pressure inside the fuel tank after driving, and haven't checked the roll-over valve yet.

But I've heard of a similar problem on an Outback, where the owner took out the floats inside of the tank, and cleaned off the contacts and/or repair it. I don't know whether the problem is inside of the fuel tank, or the fuel gauge itself.

Good luck finding your problem. The thing pisses me off too, but usually drive until the idiot light comes on anyways, so no worries for me there.

VK

Aredubjay · #3 06-04-2002, 09:39 AM

I had a similar problem with my 74 Mercury Capri. Turned out to be a loose grounding nut on the back of the instrument cluster. I havn't been behind the "Combination meter" on the SVX, but I doubt if it has grounding nuts. Still, though, it may be a grounding problem. May be in the meter, or, may be at the tank. Perhaps a corroded ground in the tank area. Just a guess.

Seraph · #4 06-04-2002, 11:06 AM

It seems like a wire short or loose ground somewhere like Randy said. On my 94, I had that problem when I hit the brake, the fuel gauge falls to E. When I hit a bump on the road, it goes back up to normal. Something is loose somewhere. And with the SVX, it's a pain to figure it out.

Lwin

Beav · #5 06-04-2002, 05:21 PM

Of course you know this is gonna cost ya another beer when I get out there.

If the ground was the problem you'd have a buttload of problems with just about everything. There's a lot of circuits depending on this one ground. However if you want to check it, for giggles and grins, it's behind the RF kick panel. Just look for an eyelet connector screwed to the metal - it should be a black wire.

The remaining connectors in the gauge circuit are located at:
LH kick panel
RF rocker (sill) plate
Top of fuel tank (naturally)
to the right (your left, looking at it with your butt pointing at the windshield) of the fuel tank.

My guess (based on my experience if nobody's been messing with the wiring, it's probably o.k.) is that the sending unit itself is the culprit, but what do I know?

Depending on how willing and careful you are, my first move would be to pull the sending unit from the tank and check it out. Use all cautions when removing it, including making certain the ignition is turned off. After removing the unit disconnect the fuel pump wiring, but leave the sending unit connected. Once you're certain you've done that correctly turn the key on and swing the float arm slowly up and down while watching the gas gauge. Or if you have a volt/ohm meter you could check it out of the car and away from the tank.

subymtnguy · #6 06-04-2002, 06:29 PM

Thanks for the reply re: fuel guage....

Are the sending units the same for the Legacy and SVX? I know where I can get a used Legacy unit if this is the problem (which it probably is)...

are there any repairs that can be done to the existing unit?

Beer?? Beav, you can have all the brewskies you want! I got it covered!

Beav · #7 06-05-2002, 07:08 PM

I highly doubt the Legacy unit is compatible, the SVX has a saddle style tank with two sending units - as far as I can tell from the schematics, anyway.

Most fuel gauge sending units have a float arm swinging a potentiometer (basically a moving point sweeping across a length of wire wound around an insulator) to vary the voltage. Sometimes the wound wire will develop a snag, the moving point will burnish or become weak, etc. It can't hurt to take it out and look at it, provided you don't cause an explosion.