Not long ago I bought a 1970 Buick LeSabre custom with a 350 4 barrel for $1,000 and only had to replace a battery and voltage regulator but now that the tanks low I went to fill it with gas and was able to get in $15 before it came back up the filler neck. So I left it alone and after driving it everyday for the last 3 days I went to fill it again and now it won't let me get any gas in. It just comes up the filler neck. The corner of the gas tank is dented a little but I can't figure out whats wrong. Anyone have any ideas? And thanks for any help. Also, I just joined so sorry if this is in the wrong place.
Defective float in tank Defective gage Possibly a baffle You may want to install a new tank when you drop it to change the sending unit. But check the tank vents first. They could be plugged.
Thanks, I'm gonna check that tonight when I get home. I think I saw the rubber lines for the vent on the right of the tank. Thanks for the help
The tank vent was blocked and when i took it off a good amount of gas came out. Then i went down and was able to get $10 in. I had to fill it slow again but it did fill back up the neck again. When i drive home and check it's not in the neck anymore and when i pulled the went out it wasn't blocked but both hoses were full of gas. Is there anything else I could do before replacing the tank and sending unit? Thanks for any help again
I wish I had a car that wouldn't take any gas, all mine seem to be thirsty all the time!! Any way welcome to the board, and I'd be dropping the tank and checking out the sending unit and vents as you've found out....
If you have a return line then check to see if it's working properly. Also make sure that if you have a vapor canister it is functioning right. Otherwise it's probably an issue with the vent system not venting correctly. Or it could be that the internal baffles are misplaced due to the damage to the tank. If the sump is pinched off it could prove difficult to get the fuel where it's supposed to go.
The vent was clogged with a black gunk that was probably the old cotton so i cleaned it out but that didn't help. I don't know if it needs cotton in it or not but it doesn't have any in it now. It also doesn't have a charcoal canister cause I looked for that too but I'll take a look for a fuel return line. I was thinking of just dropping the tank but were the straps attach it's rusty and I don't have a way around me to really fix it if it breaks. It also looked like all the fuel and break lines are original. I guess I'll check for a return line or anything else and just drop the tank if not.
Tank venting problems is by far the number one cause of PSO (premature nozzle shutoff) and spitback, including any obstruction to & from the carbon cansiter. You guys can have fun with the industry terminology...we always did too! Devon
I would replace those brake lines and rebuild the brakes at all 4 corners before taking it back to the gas station. You just never know when one of them will let go. Dual MC or not, you still need brakes. :TU:
I cannot see how the return line has anything to do with this. I still suspect the vents are clogged by debris in the tank. Siphon off the gas before you drop the tank. It is going to be really heavy if you cannot. So if the gas is still in there be prepared with a floor jack and a sheet of 3/4 plywood.
You should change all the rubber fuel hoses for sure. They probably collapsed after some 40 years of service ( provided they're still the original ones. )
Lots of good answers above, but, on more than one occasion, I have found an obstruction in the filler neck. Be it a cap from a bottle of dry gas, (most common) to a golf ball. Just something to check before replacing lots of stuff!:TU:
