samh_08

I recently did my G-body swap and all is well so far. I went to fill her up with fuel for the first time and it will not accept fuel at full tilt. I have to barely crack it for it to keep pumping.

Any ideas?

12thstreetjunkman

iTrader: (16)

do you have an evap/purge setup on it, or just a vented tank?

samh_08

Just a vent line. I do not have any emissions related devices anymore..

G-Body

iTrader: (4)

Its a new aftermarket gastank right? Sounds like the standard problem with them, they are made horribly and the venting is wrong. From the factory the fuel was supposed to flow down the bottom of the fill tube and air was supposed to flow out the top. The way the new tanks are made theres turbulence somewhere and the whole tube fills with fuel if you try to fill it faster than a trickle. I ended up putting in a 1/2" vent tube next to the main fill tube. Theres pics somewhere on here, my f-quick and el camino central.

samh_08

I looked through the pics on both sites with no luck. Could you elaborate on what you did exactly? I already have a vent line out of the sending unit but I assume that is doing me no good.

Let me know, thanks.

samh_08

Well I just found it. This would be my last resort if possible.

I assume I couldnt just swap my stock filler neck on to my aftermarket tank and be done with it..?

G-Body

iTrader: (4)

From looking at my tank it appeared that the defect was where the filler neck was placed inside the tank, so I don`t think that swapping the fillerneck would change it. No, the EVAP vent will not work in this case, it has probably a 1/8" hole for the air to push through and when you fill the tank there is a lot more air volume displaced by the incoming fuel than can fit through an 1/8" hole. So far I think everyone that I have heard of with this problem has ended up adding an external vent line between the tank and the top of the filler neck. I`m glad to see that they corrected this design flaw...LOL, back almost 5 years ago when I had this problem I called the tank MFG and told them about it.....guess that went into the circular file.

samh_08

So basically the gas is blocking the air trapped in the tank from getting out the filler neck. What is the purpose of having the vent tube on the top of the sending unit then?

G-Body

iTrader: (4)

The vent tube on the sending unit is to vent the tank while the engine is running. The gas cap seals off the filler neck so as the engine uses fuel from the tank the vent on the sending unit allows air into the tank.

cooks 7

I assume you are talking about filling the tank from a regular gas pump, here is a stupid suggestion, have you tried turning the whole filler nozzle setup upside down? For some reason that worked on a boat I used to have, not saying there isn't a problem in your venting somewhere but it's something to try to save you some hassle maybe, the only downside is you'll look like a moron at the pump, been there
Good luck!

samh_08

Haha I'll have to give that I try. If people laugh I'll just ask them where their muscle car is. Thanks for the replies guys!

ramairws6

iTrader: (33)

I won't laugh one bit. Just turn the nozzle to the side either way or upsidedown like the dude says..............should take care of your problem!

LS1GMCTruck

iTrader: (2)

What kind of vent hose fitting does everyone use, when they run a gas tank vent line up to the fill hose area? I mean at the top end of the vent hose. Does anyone sell a breather/filter for a hose ?

G-Body

iTrader: (4)

I welded a 1/2" steel tube into my tank.

buddyholly

The plastic tank out of a '95 Roadmaster I run had a vent built in the top of the tank by the filler neck running up the filler neck and back into the neck right where the nozzle goes into the filler. I wound up using my original neck cut off to fit the plastic tank with a hose running from the tank to the neck to vent it while filling.

LS1GMCTruck

iTrader: (2)

On the rear end of GM pick-ups, coming off the 10-bolt center pig, there is a vent hose that has a small vent fitting on the end. Wonder where I could get/buy one of those hose end vent fittings?

LS1GMCTruck

iTrader: (2)

Found it! Just in case anyone else ever has the need. The GM part # is: 10033125.

MalibuRacing

iTrader: (1)

I just found out I have this issue.

I have a brand new aftermarket tank, so this really sucks that I now have to modify it just to get it to accept gas, unbelievable!

I did a search and found this thread, which is dated. Has anybody found an "easy" solution to this issue?

lamdenali

iTrader: (5)

I have the same problem with mine in a Grand National wih aftermarket tank, the pump guy have to lock it on low ,I was able to fill her up for the first time since I change the tank. aftermarket sucks

samh_08

x3. I actually dropped the tank last week planning doing the fix so this would be perfect timing..

Pretty pathetic they cant make a new tank with modern technology work as well as a factory one does...