Topic: Gas Tank and Mileage
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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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?
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Former Member
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
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 !!
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.
Lifetime MemberManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
[QUOTE=ossw1]So does the 81 have a 24 gallon tank? [/QUOTE]
When I was heading over to your place last Sat. I stopped for gas. I had about a 1/4 tank or less and put in another 15 gals. Sooo maybe 18 gal. tank. I never realized the tank was that big 
. Guess I might be surprised if I check the mileage too 
. Let's see, it's 140 mi. to Santa Cruz (my daughters hang out) so that's 280 mi. rnd. trip, and we make it there and back with fuel to spare. Heck, that ain't bad. I'll check it next tankful just to be sure. That's a very strange dilemma Dave. If there is anything I can do to help, just yell.
. Guess I might be surprised if I check the mileage too . Let's see, it's 140 mi. to Santa Cruz (my daughters hang out) so that's 280 mi. rnd. trip, and we make it there and back with fuel to spare. Heck, that ain't bad. I'll check it next tankful just to be sure. That's a very strange dilemma Dave. If there is anything I can do to help, just yell. Jimmy B.
Just can't wait to get on the road again. 
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Former Member
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Mounds View, MN - USA
Joined: 5/24/2007
Posts: 1031
Vette(s): 70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe
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
Larry
Former Member
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Oak Creek, WI - USA
Joined: 5/21/2008
Posts: 1965
Vette(s): 1981 Great White Shark. Red Interior, 350/190 hp. PS, PB (SS), A/C CC, T-Tops. Served three years in Active Duty Army, then Retired Air Force after 34 years! Badger State Vettes Car Club. 175,000 Original miles!! Now own a 1998 C-5!
The fuel capacity of the 1981 is 23.7 Gallons. This is according to my 1981 Shop Manual.
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.
Lifetime MemberManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
[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 
.
! 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.
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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"
Lifetime MemberManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
[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.
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in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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