Car won't swallow?

[5thhorsemann]

Ok Here's a new one on me, I can only get the car to take 1/2 a tank of gas, like 6 or 7 gallons. At that point the fuel is topped off at the neck. Anyone see this before?

73 240Z, standard 15.9 gal tank with all new tank plumbing to expansion tank and motor. I understand that new doesn't mean good, and I may have missed something.

Any ideas before I have to dig through the hole hose thing again would be appriciated.:stupid:

[Zed Head]

Drive farther before refilling?

[5thhorsemann]

Took it down to "E" for the second time, I know the gauge is accurate, just went through the sender in the fall and stored it over winter with a full tank. Burned that out the other night. Showed almost E took just over 5, at E took just over 6. I don't know.

[Arne]

Venting not correct? Big ol' trapped air bubble in the tank?

[Zed Head]

I have read stories of tanks collapsing due to people inadvertently hooking their vent line up to intake vacuum. Any chance your tank could have something similar, or a had a blocked vent as things got cold over the winter and contracted, or somehow had the tank crushed over the winter? Have you examined the outside of the tank?

[Travel'n Man]

Pull the tank - it's not very difficult - drain the gas and go for it - an inspection will answer a lot of questions................then when it is out - change those hoses if needed.

[EScanlon]

Why not just LOOK at the tank... it's located in the rear of the car, below the hatch/trunk floor area. This might answer a LOT of questions.

It may be that the car got run up on a curb, stump, what-not and ented the tank such that it is only allowing one of the sides of the baffle insde to hold/release gas to the intake tube.

If it got dented, even a small amount, the metal may be pressing up against the bottom edge of the baffle and the other side of the baffle has become a hold.

FWIW

E

[JohnnyO]

Pretty sure he knows where the gas tank is. He did change out his sender last fall. How about some constructive advice?

Maybe something like "Run it down to E and then drop the drain plug and see how much is actually in there." or "Run it down to E and then get a clear hose and siphon out what is left into a can. If you get more than a couple of gallons you can stop because you will know your sender is not working right."

John

[tlorber]

How about filling a 2 gallon gas tank and putting it in the car. Then drive it until you run out of gas and see how many miles beyond E you got. 2 gallons should get you around 40 miles back.

[Gary in NJ]

No advice, but maybe a relevant story...

A friend of mine had a "hard" landing (slow crash) in his RV4 experimental aircraft that ended with the aircraft up-side down. There was major damage to the fuselage and VS, but no damage to the engine and wings. As an aircraft builder myself, I helped him rebuild the aircraft during the winter. He got enough test-flight time during the spring that he was able to make a long trip to Oshkosh, WI for an airshow later in the summer. During the trip he ran out of fuel and had to land on a highway. No damage and no problems as the local police allowed him to take-off from the highway (very unusual, but it happens).

When he got home we did a drain/fill test of the wing tanks. The capacity that was 16 gallons per wing when the aircraft was first finished was now 12 & 14 gallons - almost an hour less fuel then he thought he had. We looked inside the tanks with a boroscope to see if something had gotten in there to take up the space. All was clear.

Then we made a full sized wooden template of the wing to check it's shape. Sure enough, the bottom of each wing tank was pushed in about 1/2" to 3/4". It was very hard to see looking down the length of the underside of the wing, but with the template in place it became very easy to see.

When my friend had the "hard" landing, the wheels came in contact with the wing tanks; changing their shape and therefor their capacity.

So it is possible that the tank "looks fine" but is in fact miss-shaped. If not, you got to read an interesting story

[5thhorsemann]

The tank is not dented or crushed, I didn't crash or go "stump jumpin'" I did the rundown test last night with spare gas in the back, went 37 miles after hitting dead E on the gauge. Got to a gas station and she took 7.6 gallons of fuel. The gauge read 1/2 tank exactly. So its got to be tank venting.

[Zed Head]

There has to be a little voice in your head saying something's wrong with the sender, right? But subconsciously, you're thinking (hoping) it has to be okay because you just worked on it (and it was a pain to get to).

If the tank is undamaged and the gauge reads E after 6 gallons, that's the only logical conclusion. You could drain the tank contents to confirm that E is or is not Empty. I would siphon first since there is most likely about 10 gallons in there when the gauge says E. Shake the car back and forth and see if it feels/sounds like 1 gallon or 10 when the gauge is on E just to get more information.

Indications are that the gauge sender you just worked on last fall on isn't working correctly anymore.