OK, heres the problem I ran out fuel on my 81 and I thought something was not right. So when I filled up my tank I put the trip meter on to see how many miles I could get. Then last Saturday I ran out of fuel again. My gas gage does not work and I only drove 112 miles. It took 9 gallons to fill it up. Doing the math I got 12 miles to the gallon which is about right. But I should get at least 200 miles to a tank. The car did sit for a long time before I bought it. What could be some of the problems here? 

You got a locking Gas Cap ??  I can get about 230 miles on a tank (24 Gal).  It only took 9 Gallons to fill it up?  From Empty??  I'm dumbstruck !!

______________
          



(click to see a larger image)

So does the 81 have a 24 gallon tank? I have the stock white gas cap. I am tempted to drop the gas tank and replace it. I have order to replace the center gage circuit board to see if that fixes the fuel gage.

[QUOTE=ossw1]So does the 81 have a 24 gallon tank? [/QUOTE]

______________

Jimmy B.
Just can't wait to get on the road again.

 
                             Click to see larger views!

The most likely problem is the fuel pickup in the tank, which is part of the sender unit.  Unfortunately, you have to drop your tank to check, but at least that gives you the chance to check everything else.

Larry

The fuel capacity of the 1981 is 23.7 Gallons.  This is according to my 1981 Shop Manual.

______________
          



(click to see a larger image)

Yes, I did talk with another vette guy and he said the same thing about the fuel pump on the sender. That does make sense to me. Well I guess the gas tank has to come down I will plan that some time next month. All ready spent this months allowance on a new radiator.

[QUOTE=dskopp]The fuel capacity of the 1981 is 23.7 Gallons.  This is according to my 1981 Shop Manual.[/QUOTE] OOWWW ! A guy could go broke. I've never bothered to check the mileage on any of the vettes 'cause I love 'em toooo much too care, but I've never put in more than 17 gals.(oooops! I wonder if my bladder is comming loose ? I'd better run it till it's dry and see what happens. I know, I'll run out, but I'll be prepared .

______________

Jimmy B.
Just can't wait to get on the road again.

 
                             Click to see larger views!

Hey!! Looks like the virus ate my post. Anyhoo, I would have to agree with Larry. If the car sat for a long time, the pick-up line could be rotted off or broken. Would make sense if your only sucking out half your tank. Also if it had gas that sat for a long period of time it will turn to varnish. Prolly the reason why your gage sender don't work. I clean out old tanks for a livin. Usually the senders will be pretty well gummed up after a few years. "T"

______________

Click on images for Before and After pics!

[QUOTE=my7T1] I clean out old tanks for a livin. Usually the senders will be pretty well gummed up after a few years. "T"[/QUOTE]  

Terry, can any of these senders be made to work again, or do they all have to be replaced?

______________

Jimmy B.
Just can't wait to get on the road again.

 
                             Click to see larger views!

can't you just take the cap off and with a flash lite look down inside of the tank, or does 81 have a filler tube, if it doesn't, depending on how long the gas nozzle is and sticks into the tank you can still put more gas into the tank after auto shut off by raising the nozzle out of the tank and pulling back on the rubber sleeve, I fill mine about 1 inch from the top at the lower part of the opening,anips2009-07-20 19:08:57

Yes I could do that but what would that do just give me 145 miles vice 112? Taking down the tank is no big deal. I will paln that for next month Jimmy you up for it?

[QUOTE=ossw1]Yes I could do that but what would that do just give me 145 miles vice 112? Taking down the tank is no big deal. I will paln that for next month Jimmy you up for it?[/QUOTE]

______________

Jimmy B.
Just can't wait to get on the road again.

 
                             Click to see larger views!

[QUOTE=aceinthehole][QUOTE=my7T1] I clean out old tanks for a livin. Usually the senders will be pretty well gummed up after a few years. "T"[/QUOTE]  

Terry, can any of these senders be made to work again, or do they all have to be replaced?[/QUOTE]

Hey Jimmy. Sorry it took so long for response. Just got back from vacation. It would depend on the condition of the sender. If its rusted up where the contacts no longer work it would need replace. Plus the float may be stuck from the gum inside. They can be cleaned or sandblasted, but if you go through the trouble of pulling the tank, I would recomend a new one. Hope this helps. "T"

 

______________

Click on images for Before and After pics!

You bet it helps Terry. I've got a couple of these to do and I like to go in heavily armed with information.

______________

Jimmy B.
Just can't wait to get on the road again.

 
                             Click to see larger views!

Before you get into the fuel tank, did you try changing the fuel filter? Sometimes by running the tank dry, you can suck up enough dookey to plug the filter. Then the dookey floats back for a while and will replug the filter.