I've got gas..

whoops · 10-30-2002, 12:25 PM

Hi all.
I have an intersting gas issue for everyone.

I have an '89 LX 5.0L with a 14 gallon tank (I think it's 14?)

When the gas tank is lower than 3/4 to 1/2 of a tank and I take a hard left hand corner gas ends up in the fuel filler area. (open the side door and stick the gas handle in...) I can't find out where this is coming from. I've replaced the gas cap twice and for kicks re-sealed the filler hose lip to the body. Is there some sort of return hose or something that could be spitting the gas in there? I'm at a loss.

Thanks,
Justin

fiveohpatrol · 10-30-2002, 12:56 PM

I think there is a check valve in the fuel tank filler neck. Yours may be stuck open.

Pull it out of the tank and give it a check.

whoops · 10-30-2002, 01:03 PM

Hi FiveO,
Mustang Newbie here, can you be a touch more specific on where this item is located and what it actually is?

Thanks!
Justin

fiveohpatrol · 10-30-2002, 01:17 PM

a check valve is pretty much just a flap inside tubing. It allows flow one way, but not the other. When a fluid tries to reverse its flow, the valve shuts and doesnt allow it to pass. I'm pretty sure that the filler neck (the tubing that goes from your gas cap to your tank) has a check valve that only allows the gas to enter the tank, and not go back up the tubing. Your valve however, could be stuck open, thus allowing the gas to flow up the filler neck and into the gas cap area.

To remove the neck, you will need to remove the 3 bolts from around the gas cap area and also drop the fuel tank. The tank has 2 straps holding it up held by 2 (1/2" i believe) bolts. Make sure you run the thing to close to empty (because a full gas tank is heavy

) and then get a friend to give you a hand in lowering it. You won't need to disconnect any lines or connections to get the filler neck. But it is a little bit of a pain to get the neck out of the tank. You just have to snake it out of there, then see whats goin on. You may be able to lubricate it, or get one from a junk yard.

Are you sure it only happends when its less than 3/4 of a tank? that seems somewhat odd.

whoops · 10-30-2002, 01:35 PM

Yes, it only appears to happen with less fuel. The less there is the more likely it is to happen during a hard corner. I've filled the tank and cornered hard to test this out, only starts happening near the 1/2 mark.

By the way, putting the new fuel cap on did help the problem but it's still occuring.

I did notice some darker patches on the tank itself near where the filler neck would go in, and it smelled slightly of gas. Possible leak there as well, or overflow from above? Think it'd be a good idea to replace the tank as well as the hose, or just the hose?

Thank you again for all the assistance.

Justin

10-30-2002, 12:25 PM	#1
whoops Registered Member Join Date: Oct 2002 Location: Broomfield, Colorado Posts: 53	I've got gas.. Hi all. I have an intersting gas issue for everyone. I have an '89 LX 5.0L with a 14 gallon tank (I think it's 14?) When the gas tank is lower than 3/4 to 1/2 of a tank and I take a hard left hand corner gas ends up in the fuel filler area. (open the side door and stick the gas handle in...) I can't find out where this is coming from. I've replaced the gas cap twice and for kicks re-sealed the filler hose lip to the body. Is there some sort of return hose or something that could be spitting the gas in there? I'm at a loss. Thanks, Justin __________________ Justin '89 LX 5.0L AOD, notch back (STOLEN 11/21/02 at 4 am!)

10-30-2002, 12:56 PM	#2
fiveohpatrol I'd rather be basketweaving Join Date: Feb 2000 Location: Indianapolis Posts: 2,551	I think there is a check valve in the fuel tank filler neck. Yours may be stuck open. Pull it out of the tank and give it a check. __________________ NMRA O/C 9516 NA pumpgas stickshift 347 10.65@125.6, 6.73@100, 1.41 60ft

10-30-2002, 01:03 PM	#3
whoops Registered Member Join Date: Oct 2002 Location: Broomfield, Colorado Posts: 53	Hi FiveO, Mustang Newbie here, can you be a touch more specific on where this item is located and what it actually is? Thanks! Justin __________________ Justin '89 LX 5.0L AOD, notch back (STOLEN 11/21/02 at 4 am!)

10-30-2002, 01:17 PM	#4
fiveohpatrol I'd rather be basketweaving Join Date: Feb 2000 Location: Indianapolis Posts: 2,551	a check valve is pretty much just a flap inside tubing. It allows flow one way, but not the other. When a fluid tries to reverse its flow, the valve shuts and doesnt allow it to pass. I'm pretty sure that the filler neck (the tubing that goes from your gas cap to your tank) has a check valve that only allows the gas to enter the tank, and not go back up the tubing. Your valve however, could be stuck open, thus allowing the gas to flow up the filler neck and into the gas cap area. To remove the neck, you will need to remove the 3 bolts from around the gas cap area and also drop the fuel tank. The tank has 2 straps holding it up held by 2 (1/2" i believe) bolts. Make sure you run the thing to close to empty (because a full gas tank is heavy ) and then get a friend to give you a hand in lowering it. You won't need to disconnect any lines or connections to get the filler neck. But it is a little bit of a pain to get the neck out of the tank. You just have to snake it out of there, then see whats goin on. You may be able to lubricate it, or get one from a junk yard. Are you sure it only happends when its less than 3/4 of a tank? that seems somewhat odd. __________________ NMRA O/C 9516 NA pumpgas stickshift 347 10.65@125.6, 6.73@100, 1.41 60ft

10-30-2002, 01:35 PM	#5
whoops Registered Member Join Date: Oct 2002 Location: Broomfield, Colorado Posts: 53	Yes, it only appears to happen with less fuel. The less there is the more likely it is to happen during a hard corner. I've filled the tank and cornered hard to test this out, only starts happening near the 1/2 mark. By the way, putting the new fuel cap on did help the problem but it's still occuring. I did notice some darker patches on the tank itself near where the filler neck would go in, and it smelled slightly of gas. Possible leak there as well, or overflow from above? Think it'd be a good idea to replace the tank as well as the hose, or just the hose? Thank you again for all the assistance. Justin __________________ Justin '89 LX 5.0L AOD, notch back (STOLEN 11/21/02 at 4 am!)