82CEzeke

hey guys my fuel gauge always shows as full even when its empty and even when my car is turned off. any ideas what i need to do to fix it? do i need a new fuel gauge?

Jbster

Could be your gauge or sending unit.

http://willcoxcorvette.com/instructi...68-76_ver7.pdf

hugie82

Is it hovering around fuel or is it pinned? Hovering around fuel is sometime the float getting hung up. Your might be able to see it through your gas filler and move it with a coat hanger or you can undo the bolts around the filler and pull it. If you're gonna go that far, just replace everything. It saves a lot of headaches down the road.

82CEzeke

i haven't checked that. would i just look down the fuel hole? if i were to replace everything, what would everything be?

in what scenario would i have to buy a new fuel gauge?

dpw21562

I had the same thing and replaced the sending unit and that cured the problem.

hugie82

With the tank low on fuel, you can take a small light and look down the filler neck. The float is a about the size of a zippo lighter and it's yellow or off white usually. That's the part that floats on top of the fuel and gives the gauge it's reading. Move that with the coat hanger and see if the gauge changes. If not, order the sending unit, gasket and fuel pump. Some times you can get it as a complete unit , other times you have to piece it together.

82CEzeke

Cool thank you if all else fails I will get a new sending unit

82CEzeke

Ok I will try this out hopefully it works. Do I have to wait till I think it's on Empty or can I do it sooner?

stevelischynsky

My new 73 showed full once many yrs ago. I looked into the tank and saw that the fuel was done a lot. I took a small stick and gave the float a tap. It dropped with a clunk, the gauge went back to normal. Never saw that problem again. For some reason it was a once thing only


Steve L
73 coupe since new

82CEzeke

Cool thank you I will try this. I hope it's that easy!! So I just get a stick or hanger and poke around in there?

stevelischynsky

Ya, I would use a stick rather than something metal. But don't over do it. it just takes a small poke. But check to see if the float is high first. If the float is already low, then that is another problem.

I never looked into why it hung up since it was a one time thing only. I'm also looking at 30 yrs of memory as well.

steve L
73 coupe since new

82CEzeke

I tried poking in it but got nothing. I tried to look in to it too but the hole was too dark and small. Do you know how I would remove the whole sending unit?

stevelischynsky

Use a flashlight to look in. If I remember correctly, you can actually hook onto the float with a stick and pull it up gently to make sure it is free.

I'm not sure about your yr but you would need to remove the ring on the bottom of the fuel tank. The float and pickup then drops down along with all of your gas. You probably want to drain the gas first in a controlled fashion by removing the pickup hose.

But I would read and understand the Wilcox link further up on this thread before you start undoing things. It is an excellent write up.

Steve L
73 coupe since new

82CEzeke

Ok thank you I will review the Wilcox link and see if I can take it apart because I really don't want to spend the money on a new fuel gauge haha thanks again!

gsixl

Possibly be a wire grounded between sending unit and fuel gauge.

82CEzeke

What does a wire grounded mean?

0Willcox Corvette

Put an ohms meter on the sender and see what the ohms reading is. Then have someone else carefully push up and down on the car and see if he reading changes.

Jbster posted you the paper for 1968-1976 that is on our site, here is the one for your car. Everything you need to solve the issue should be the article below.

Corvette Fuel Gauge and Sending Unit Testing 1977-1982

But one last question.

By pegged full, is the needle just above the 3 o'clock position? Or is it just pointing to full.

With no ohms input, the gauge will read as pictured below.


If it is sitting on full only, pull the ohms wire from the sender and see if it reads like the picture above, then ground this wire out and see if the dash unit goes to the empty side.

If you are getting ohms at sender yet there is no change when the car is shaken, then you possibly have either a defective sender or you have fuel behind the bladder and the bladder is holding the sender in place.

Willcox

gsixl

If not mistaken the sending unit grounds the wire to the gauge as the tank fills up it is then fully grounded when full. So if the wire between the sending unit and the gauge is grounded out some where the gauge would then show full all the time.

0Willcox Corvette

If the sender (ohms) wire is grounded out, the fuel gauge will peg to empty. When the gauge is missing ohms input (broken wire or the wire has fallen off), it peg's like shown in my picture above... exactly to the top of the rivet.



Willcox

82CEzeke

Yes that is how my gauge looks! It is at 3'oclock!