Gas gauge woes

So ever since i got my car my gas gauge has always been fishy. when i fill it up it'll show full, when its near empty it'll show empty. If i drive it hard just to merge onto a highway, the gauge will go down like 1/4 or even half of the way and slowly go back up and i mean really slowly. if the tank is a 13 gallon tank, im only getting like 250 miles out of a tank. so whats that like 19 mpg? i mean Is that somewhat normal? I don't know if all e30 gas gauges act like this.

mine does the same thing mang....sometimes i can put in 2 gallons and it will read full, then as i drive down the road the light will come on, finally it will settle where its supposed to be....
except im getting right around 320 miles per tank, but mines an eta and you have an I

IIRC e30 gas gauges are measured by a floating device, when you speed up or slush the fuel around it makes that device go down or up accordingly. mine never had any issues cuz there were drilled holes in the bottom to allow fluid to escape and enter quicker. this happens with all the cars in my driveway, even the 06 van thats here.

That's what i thought. I checked it out today after it's been parked all night and now its back up to just below a half a tank when last night i pulled in it was below a 1/4 of a tank. Is there any way to fix this problem? new floating device or something?

Originally Posted by E30-325

That's what i thought. I checked it out today after it's been parked all night and now its back up to just below a half a tank when last night i pulled in it was below a 1/4 of a tank. Is there any way to fix this problem? new floating device or something?

about the only thing is to drill holes at the bottom of the float like steve said

Originally Posted by downhiller

about the only thing is to drill holes at the bottom of the float like steve said

How many holes? what do you guys suggest?

Originally Posted by E30-325

How many holes? what do you guys suggest?

mine just had 2 x 1/8" to 3/16" size holes, they were on opposing sides. just make sure you do it with the mechanism upside down so you dont drill through the floating device. drill them about 1/4" away from the bottom.

Originally Posted by fcsteve

mine just had 2 x 1/8" to 3/16" size holes, they were on opposing sides. just make sure you do it with the mechanism upside down so you dont drill through the floating device. drill them about 1/4" away from the bottom.

Nice! sounds good im gonna go do it now.

Did it work? I may also try this, mine says empty and still has 2 to 3 gallons left.

Originally Posted by JohnMadd

Did it work? I may also try this, mine says empty and still has 2 to 3 gallons left.

well i was going to do it today but i realized i have a half a tank so im gonna use as much gas tomorrow and do it with like less than a 1/4 of a tank because i dont want to drain the tank and spill gas everywhere.

Originally Posted by E30-325

well i was going to do it today but i realized i have a half a tank so im gonna use as much gas tomorrow and do it with like less than a 1/4 of a tank because i dont want to drain the tank and spill gas everywhere.

the level sender is on top of the tank, you can remove it even with a near full tank. just make sure you dont blow through the side with the drill and make sure yuo shake out as many shavings as you can.

That's helpful

Sometimes the fuel gauge (temp. gauge as well) behaves strangely because of a bad ground. The back of the dash cluster has two brass studs with nuts which loosen or corrode over time. Many people clean/retighten these and their gauges work much better. There is also a grounding point on the steering column with many brown (if I recall correctly) wires meeting at one point, sometimes poor contact at this area also causes problems.