i kno this is common but i tryed to search feature i couldnt find what im looking for but is there a way to fix this

 

My car 93 does this too.

 

the gauges are just inaccurate, both my lt1 camaro and ls1 trans am does this too. i think maybe an aftermarket gauge and sender might help but thats if it bothers you enough.

 

F-bodys have consistently had this problem. my 95 formula did it, but thankfully my 95 z28 doesn't do it.....yet. The problem is a faulty sending unit in the tank. You can replace the sending unit, but if you do you either have to cut a hole in the fuel tank, or drop the tank. either way, to me, its not worth it. just fill up before 1/4 tank

 

the gas tanks in these cars are trapezoidal, but the sensors are calibrated for a cubical-shaped tank. so, when there is a half-tank of gas, it's really less due to the decrease of volume as the shape of the tank goes down.

 

I can run mine all the way down to E, After the first quarter it just goes fast cause of the reason stated above.

 

Dont you mean cut a hole in the trunk compartment?

 

When I've filled up the tank, the gauge goes way past F (straight up). The
gauge "accelerates" down over mileage driven; by the time it gets to 1/4
tank, it's showing "normal". Mine does go to E.

I get piece of mind by setting my trip odometer everytime I fill up, knowing
I can get around 240 miles to a tankful.

 

mine is a 93 and does it all the time.just fill it before a quarter tank.

 

yeah you cut a door in the trunk...not in the tank..

 

Mine didn't start doing it until I installed my Walbro 255..it goes dry at the 1/4 mark, I killed a set of Plugs when it did it. Basically I found out the hard way.

I'm thinking about trying this..it will be easy since I already have the "Trap-Door Mod"..

Taking out the whole Sending Unit, holding it as it would sit in the Tank, moving the Level Rod with the Float on it to where the Float would be even with the bottom of the Sending Unit right before the Pickup Filter, and bending it to where it would read Empty at that point.

I think that would solve that problem..I have to try and see when I get bored.

 

I've never had the tank go empty at 1/4, it just drops from 1/4 to E pretty quick.

 

yeah mine does this as well. Actually I found this out after driving home from picking up the car and ran out of gas on the interstate and had to push the car UP the off ramp to get to the gas station and then fill it back up. It took me and my nephew about an hour to push it up the ramp and then let it roll down the hill to the closest gas station. So yeah this must be a VERY common problem.
Hope someone can find out how to fix this.... Merv, LMK if that works....

James

 

Check "sdm1234"'s post - there isnt a fix, unless you go with a symmetric tank.

 

When the stock fuel pump went out in my car @ 100K, I upgraded to a Walboro pump. As I was putting it back together, I decided to check the gauge before getting too far along... The sending units are supposed to be 0-90 ohm (empty=0,full=90) - I found the range on mine was about 12-120 ohms. I should've replaced the sending unit, but @ 12 ohms, the needle was just barely above horizontal on the gauge. When it's full, it's WAY past vertical. I think I can go about 200 miles and the gauge shows half full... Past that it moves very quickly toward E. The only way I could think of to fix it would be to splice in a device that could translate the bad signal range (12-120 in my case) to the standard 0-90 range. Any EE's out there?

 

Not to beat a dead horse (I guess we are at this point), but it's not really
about ohms here - it's about the shape of the tank and the fact that the
sensor is not designed as such.

Run back and read, 'sdm1234', reply.

 

When I get the chance to check it out I'll let you guys know..

 

Maybe I misunderstood the topic of this thread, but the tank being empty, while the gauge shows 1/4 left, is all about the ohms, and a faulty/inaccurate sending unit. Even if it's the opposite situation, where the tank is at 1/4 of actual fuel, but the gauge reads empty, it's still an "ohm" issue. Merv's suggestion of bending the float arm may work in that case.

 

It's about the only way I really see it working.. It pisses me off to know that about the Car cause it just one of them things wrong that even if you only know it, it's still there.. you know..

 

Really? So, If Merv "bends the float arm", is that related to electrical or is
that related to "mechanical" ? See my point? Does the fact that the tank
is not "rectangular" fit into this equation? Plus the fact that the float/sensor
conforms only to rectangular tank(s) - does that not enter into this
"unbalanced" equation? It's simply a mis-match of the odd-ball shaped
tank using a standard float/sensor.

Let's think of this another way. Ever see a Hurricane (drink) glass? Notice
the shape is wide at top, goes thin, then goes fat again. As you take a drink
from the beginning, it doesnt seem you've done much damage (unless you
gulp the damb thing). Then you get to the thin portion of the glass - when
you take another gulp, it seems the drink is dissipating faster. Then when
you get to the bottom end of the glass, things go slower.

Same concept, but in reverse