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Topic: 13-14 gallon tank? (Read 3295 times) previous topic - next topic

13-14 gallon tank?

My Coug ran out of gas on me once before (or could have just been a stall) when the needle stayed on E for a bit. I recently let it get to E and filled it completely (I could see the gas level from the filler neck) and it was only 12.9 gallons. The needle rises and falls as if the float and needle are operational. Given the amount I drive I fill up roughly every 4 days like clockwork. I thought I should have over 20 gallon capacity. What would be a good way to check?

13-14 gallon tank?

Reply #1 –
The gas gauges are inaccurate. After I fill up I go for over 100 miles before it drops below full.
What kind of milage do you get? If it is normal then you probable have a lot gas left at "empty".

Carry a gas can with you and see how far after "empty" you go before you run out.

13-14 gallon tank?

Reply #2 –
I'll definately do that. I was going to try and siphon gas from my other car but new cars are the worst for that.

I have tried to calculate the mileage but it sucks with such a wacked out gauge.

13-14 gallon tank?

Reply #3 –
We have 22 gallon tanks.
1988- 3.8- T-bird- sold 2005 Grand Prix, GTP- COMP.G MODS: Inferno Hood, GXP spoiler, Liquid Metal Wheels,K&N Intake,LED taillights,LED reverse lights, LED interior lights, 180*,605s, Pacesetters :burnout:

13-14 gallon tank?

Reply #4 –
This has been talked about in the past, probably buried 20 pages deep by now.  I've personally ran my car down to the point it was stalling pulling into the station.. and it still held less than 16 gallons... that being in a 88 (87 and 88 having the 22 gallon tank, earlier years having an 18 gallon. I think)
One 88

13-14 gallon tank?

Reply #5 –
Factory specs:

1983-85 V6/V8 cars - 20.6 gallons
1983-86 turbo-4 cars - 18.0 gallons
1986-88 cars (all engines) - 22.1 gallons

Filler neck holds approx. 1 gallon, in case you wondered. ;)

Quote
My Coug ran out of gas on me once before (or could have just been a stall) when the needle stayed on E for a bit. I recently let it get to E and filled it completely (I could see the gas level from the filler neck) and it was only 12.9 gallons. The needle rises and falls as if the float and needle are operational. Given the amount I drive I fill up roughly every 4 days like clockwork. I thought I should have over 20 gallon capacity. What would be a good way to check?

There are a few other factors that may come into play here. What is the distance that you drive every day, one way?
You also may have a fuel leak either at the tank or at the injectors.
Are you getting a strong gas smell?
How about your charcoal cannister in the engine bay...is it full of fuel? Strong odor?

13-14 gallon tank?

Reply #6 –
My 84 owners guide agrees with Eric but also shows a 21 gallon tank for 3.8L Canada cars. They would be carb. cars. The in-tank pump takes up .4 gal. of space maybe?

The shop manual says the tanks have a "fill limiting" system to allow a 10-12 percent tank volume air space.
This allows for thermal expansion of the fuel and is needed for the vapor vent system.
It doesn't say if this is additional space over and above the 20.6 gallons or what.

13-14 gallon tank?

Reply #7 –
There is no gas smell anywhere. I drive almost 75 miles a day. The gas consumption does not seem out of the ordinary for the distance I drive. 13 gallons seems to be all can get in the tank. I have had fuel up to the rim of the filler neck at 12.9 gallons. The needle is touching E right now and i'm headed to the gas station to get an emergency can of gas for the trunk. If I indeed has a 20 gallon tank then I have roughly 7 gallons left even though the needle is on E. I should make it to Friday morning but we'll see.

13-14 gallon tank?

Reply #8 –
I was able to squeeze 17 gallons into the tank and that is from a pretty dry gas tank. If I hit a turn too fast the fuel pump would suck air and stall.

I must be running extremely rich as I am only getting roughly 10 mpg. I know I need to replace my TPS (pulled codes a while back) and a few other minor parts.

13-14 gallon tank?

Reply #9 –
Could a turbo tank have been put in it?
Does it have a dent in it?
Does it have a secret compartment where drug runners used to hide cocaine?

13-14 gallon tank?

Reply #10 –
I doubt the tank was replaced. It could be possible. There are very small dents in the tank but not 3 gallons worth. If there is a secret compartment for drugs (and the drugs are still there) then I would like to know so I could make some fast money to finish this project.
:2gunsfiri

13-14 gallon tank?

Reply #11 –
It has been a long time since I have been inside a gas tank.
My son had a '71 Torino 30 years ago that would only take a half tank of gas.
The filler pipe in the rear center behind the license plate had been bumped and tipped down deeper into the tank. The vent tube was attached to the filler pipe and was also tipped down deeper into the tank.
The vent was supposed to curve up to the top of the tank but was now down half way into the tank.
When the gas level got to the end of the vent tube, no more air could get out, and no more gas could get in.

The gas gauge on my 84 T-Bird pegs above the F and finally moves down to F after about 110 miles.
Maybe your missing space is above the Full mark. I have not been inside these Fox tanks so do not know how they are vented.

If your tank stops venting before it is full that could explain it.

13-14 gallon tank?

Reply #12 –
The interesting thing is that the gauge reads over F when I have it filled to the brim. To fill up from well under E to over F is only 17 gallons at best.

If it is my gauge, then could the fix be as simple as swapping in a new one or is there more work involved?

13-14 gallon tank?

Reply #13 –
As the gas fills up I noticed it coming out of the vent. I'll have to investigate that one.

13-14 gallon tank?

Reply #14 –
Check the charcoal cannister in the engine bay...more than likely it's either full of gas, or the charcoal inside has disintegrated.