Gas tank Question

[Cethern]

Hello

I have a 75 280 with I'm sure a lot of crud in the tank as I only get about 150miles per tank and fill with 8/10 gal at a time. Now I have done a search and I have not found what I'm looking for yet.

My question is...I have found a 77 280 tank on ebay will that fit in my 75? From what I can tell it should.

I would pull the tank and get it cleaned and coat the inside. But the little car

is a daly driver. Thank for the input

Eric

[EScanlon]

Are you sure that it hasn't been halfway crushed? You'd be surprised at how many tanks I've seen that had been backed into curbs.

FWIW

E

[280~Master]

that 77 tank will fit in the slot but your fuel pump will be different. On a 77 the pump is in the tank. Your 75 has the fuel pump behind the passenger tire. This would be a little work to convert but it could work. Look for a tank thats from 74 to 76. 260 or 280.

[Cethern]

Thank you for replys

EScanlon: The tank does not have any big dents to warrant using only 10.4 gals out of a 17 gal tank. but I have given thought to the pickup tube broke off. But when I lose power and die on the side of the road. Then restart it to where it runs for a few more miles has me thinking the tank has a lot of rust.

280~Master: Thanks for that info I need to read the FSM a little more I guess

And I'll let that other tank I have a bid on go by if I'm out bid that is. I need to hit the Bone yards and look around some. a few that I have called are out of tank..must of rusted away

Eric

[agemeansnothing]

You should find a shop arround your area that hot tanks gas tanks.

[MikeW]

Then restart it to where it runs for a few more miles has me thinking the tank has a lot of rust.

It may well have a lot of rust that's clogging the fuel filter. However, even if the entire tank itself rusted away completely there's simply not enough metal there to amount to more than about a gallon's worth of rust. Something else is accounting for your missing capacity.

[EScanlon]

I mentioned the tank being dented, because there IS an anti-slosh baffle located in the centerline of the tank, going from front to back.

IF the tank got hit just right, it is highly conceivable that the outer skin of the tank has been crushed up tight against the baffle and trapping or daming several gallons worth of gas behind it's "dam". That it isn't a perfect dam would allow for some gas to seep under it and allow you to re-start and run until once again, your demand had overcome the supply.

Granted, may be a bit of a far-flung possibility, but unless you have several pounds worth of .... something.....taking up 6 gallons worth of space, (5 if you presume that you weren't towed or pushed into the gas station), that's STILL a lot of space to mysteriously lose.

Now, I'm going to ask another "stupid" question.

Are you reporting 150 miles from fill up to ....

1 - when your gas gauge reads Empty and YOU decide to fill up again, and can only get 10.4 gallons into the tank before it fills up? That is, you decide to fill up before you get stranded.

2 - when you run completely out of gas, and even if you were to wait overnight you STILL wouldn't have enough gas to get home? That is, you ARE stranded.

(That you sometimes lose power and the engine quits and can be re-started later and run for a few miles may be an indication of vapor lock and not necessarily running out of gas. The bent pick-up tube wouldn't allow you to once again pick up gas once the level of the gas is low enough for it to suck air....unless some gas is trickling back into the tank (which it does) or the gas is somehow expanding in volume.)

If it is YOU deciding to re-fill, have you considered that it is entirely possible that your gauge is off by a good amount....that's not at all unusual to have as a situation. Changing the sender unit changes the readings at the gauge and vice versa. The two (gauge and sending unit) are a matched pair.

Before I would presume that you have enough crud in your tank to fill up a 5 gallon gas can (unless your car was used as a drug-runner), I would investigate the other possibilities.

2¢

Enrique

[First Gen Z]

It's not that big of a job to remove the tank and look inside.

[Cethern]

EScanlon: you bring up some good points to ponder.

I had a local Mec. knowen for Z cars look at the tank his first thought was a dent as well but the ones there are not bad, small over all but your point about a baffle could hold water.

When I stated the 10.4 gal my OD was reading 150. +/- at the time when I fill the tank I go to the top. I have gotten a little over 200 mpg mostly hiway.

But either way still the same spot on the gauge about 1/4

Now before I took this little gem home I took it for the second test drive and the gauge was well below where I get it now. on that test drive I put 5gal in it and after I took it home (the same day) I put another 10gals. in it.

My thought is there is a lot of crud in the tank and when I get down low enough the crud has less room to float around and the pickup gets it. when I stop the engine the the crud is no longger being sucked up. and after I restart I'll get a little ways down the road before it happens again.

I have changed the filter The gas that came out was rust colored.

Right now I will still try and get that tank on ebay and get my 72K5 up and running so I can pull the tank right now the car is the only mode of trans.

I have given thought to pulling the drain plug and see if that helps get the crud out even for a little bit.

Eric

[EScanlon]

Get a small can of gas....a one gallon or 2.5 gallon is sufficient. Then run the tank dry, THEN check to see how much it takes to fill it and you only have to consider the one or 2.5 gallons you put in.

Drainnig the tank is not at all a bad idea, especially since you suspect that there's crud in there. Again, run the car until you get to that point where it starts cutting out on you, and then get it home, drain and if possible filter the gas (rather than throw it away).

That you're using your odometer to determine when to fill more than your gas gauge, says you know that it is inaccurate.

Check those out and then see what you find.

Enrique

[Mat M]

If you are dead set against dropping the tank to do a thorough clean-out/inspection/inner lining (your best bet, overall) try this:

Top off your fuel tank (with gasoline) and put in a product called SeaFoam. You will be able to find it at any NAPA or Riebes. Drive around, let it swash around (carry about 5 fuel filters with you at all times, as well as a straight-bladed screwdriver). Then filter while draining the tank as EScanlon suggested. You may have to repeat if there is as much gunk as you suggest.

I haven't installed a liner on my car, but in one weekend, I pulled the tank, poured in 1/2 gal of MEK (you can get 1 gallon cans of MEK in the paint department of any hardware store), let it sit overnight, agitated the tank, and rinsed. I repeated the next night just as a precaution, and reinstalled the CLEAN tank. Besides the waiting part, and the drying time, it was about 2 hours. If you don't want to wait for the drying time, you could rinse with a bottle of isopropyl alcohol after the water washout of the MEK. Good planning, and you can do this on one night and the next day. (pull the tank, add MEK on Sat. eve; agitate, dump MEK, reinstall clean MEK Sun morn.; agitate and dump MEK Sun eve, rinse, washout with isopropyl, reinstall sun night!!)

[Virto]

I'd just rock the car. I know when you rock my 280, you can hear gas slosh around, even if there's less than a gallon in there. The sloshing sound becomes pretty pronounced if there's a lot of gas in the tank.

Sombody could have dumped a ton of sugar in the tank I suppose. It doesn't dissolve in cold gas, and the mythbusters determined it isn't enough to stop a car from working just fine.