Recent Topics
185/65/15 to 205/65/15 on Nissan Versa
by wn1998
12/21/14 05:30 PM
Bought life insurance lately?
by Cadenza
12/21/14 05:24 PM
What Oil Are You?
by 84zmyfavorite
12/21/14 05:20 PM
4.5 bolt wheel on 4.52 car.
by GreeCguy
12/21/14 04:31 PM
Open headers
by GreeCguy
12/21/14 03:54 PM
0W40vs 5W40 in 2015 VW Golf?
by Revrick
12/21/14 03:18 PM
Any experience with Mag1 motor oils? Synthetic?
by slapshot111
12/21/14 03:14 PM
Highway, 1 Hellcat owner, 0
by Trajan
12/21/14 03:10 PM
Oil residue in exhaust tips after oil change
by jjgen13
12/21/14 02:09 PM
How can you tell if your car has flat-tappets?
by OceanRuns
12/21/14 01:43 PM
Sick coworkers Insisting on Coming to Work.
by tom slick
12/21/14 01:20 PM
Can't Reach Spark Plugs
by Nick1994
12/21/14 01:00 PM
Newest Members
consolidated, mike_a, dlayman, BRader, GuySir
52259 Registered Users
Who's Online
122 registered (aa1986, 95busa, abycat, 97f150, 2010_FX4, AandPDan, 9 invisible), 1542 Guests and 231 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
52253 Members
66 Forums
223758 Topics
3548663 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Page 2 of 2 < 1 2
Topic Options
#3311682 - 03/14/14 11:17 AM Re: Gas coming out of tank while filling [Re: Tom NJ]
hsd Offline


Registered: 09/05/09
Posts: 228
Loc: NE
The charcoal canister can not cause overflow during filling as it only functions when the system is sealed up (gas cap is installed).

Top
#3311978 - 03/14/14 04:14 PM Re: Gas coming out of tank while filling [Re: Tom NJ]
1 FMF Offline


Registered: 08/12/02
Posts: 1546
Loc: CT
when i had the back of my 2006 gmc sierra apart, i found that there's a valve in the filler neck of the fuel tank that's spring loaded and stays shut unless a force acts from outside to push it inward, such as fuel when filling. the purpose of it is to prevent fuel from coming out in case of a rollover. i believe all gas tanks have this, and also makes it nearly impossible to siphon gas out of the tank because it will block any hose from making it through. my guess is that valve is sticking or not opening all the way preventing any significant volume of fuel from entering the tank quickly. otherwise everything else is sealed, the evap canister and purge valves are always closed unless commanded open by the pcm. your vent for when filling the tank is a separate small hose that runs alongside the big fill hose and goes to the filler neck thing up on the body where your gas cap is. if you look where you insert the gas pump into that fill neck, there will be a separate small hole there, that's the vent which works when filling the tank because the gas cap is off. but when the gas cap is on then the fuel system is completely sealed.


Edited by 1 FMF (03/14/14 04:16 PM)

Top
#3311989 - 03/14/14 04:22 PM Re: Gas coming out of tank while filling [Re: Tom NJ]
1 FMF Offline


Registered: 08/12/02
Posts: 1546
Loc: CT
also gas with ethanol is quite a solvent, also attracts water, and over time can dry out that plastic valve and make it stick or corrode/rust the metal spring. using some kind of oil, like marvel mystery oil, which you can run with little problem in the fuel, shoot that down the fill neck every now and then to coat that anti-siphon valve and it may get better. otherwise if it's integrated into the plastic tank then you're looking at a new fuel tank.
but don't dump a pint of mmo down the fill neck just before filling up with gas and wash all the mmo down, that'll defeat the purpose.

Top
Page 2 of 2 < 1 2