I know the forum has several threads but this one presents differently.

I recently changes out the fuel pump, filler neck and hoses. Then replaced the leaking fuel lines. Yes the fuel filter was replaced as well.
Last May replaced the vent valve and dumped an enormous amount of eastern Oregon dust out of the hose and filter.

For about 3 weeks all was fine until December 6th when stopping gas the pump wouldn't stay on. Had to fill very slowly. Have checked and am paying a mechanic to verify that the hoses are not kinked from filler to tank and vent valve is open. No debris or gas was found in the hose or cannister.

2001 ZR2. for reference

Can the anti siphon device have swelled? Or something else?

 

I had the same problem with my old equinox. Was told it was a vent sticking shut, preventing the back pressure of the air/fumes coming out when the gas if filling up... making the gas nozzle think its gas pushing back.

my ex totaled the car before problem was fixed, sorry if this doesn't help lol

 

Found the issue the Spectra FN741 filler neck I installed failed. The anti siphon ball swole up and blocked the filler neck. Of course the 30 day return window passed..

 

Plugged carbon cannister if the vent valve is replaced and working.

When you shut key off, vent valve opens and tank is vented to atmosphere through the carbon cannister. If you put gas in the tank, the displaced air needs a place to escape.

 

The snti siphon or rollover device has swelled to the point it blicks the oath fir fuel to reavh the tske. This is a Spectra aftermarket unit.

 

Look up by your gas tank in the rear. There will be a black box with hoses and a plug on it. That is your gas tank vent or purge valve. It lets your tank vent as you fill. If it stops working, you can only pump a little at a time before the pump clicks off. Most of the time, this only needs cleaning. Remove it, snap it apart and dujp the dirt out of the sponge filter in there and replace. Be sure to blow through vent hose to make sure it is clear also.

 

Both myself and the shop checked the vent valve and checked the vent canister and hoses for blockages and found none.

The fix in this case was to install the original filler neck. The truck filled normally after that.

Please look at the picture in my response above. The anti siphon ball is no longer round and blocking the path for gas to go down into the tank.

 

Hello. Being its not really an old thread thought id ask. where did you get the neck from. I have a 04 blazer ls 2 door and same issue.. try to fill tank shuts off in like 2 seconds. reason i ask is because rockauto.com has the spectra fill neck but the part number is different. (SPECTRA PREMIUMFN742) so i am wondering if they updated the design to fix that problem you had.

 

never mind. the 04 is a different number then 02 and older. the FN741 is for 02 and older. so i am wondering if i still should order it..lol.

 

I will let the pictures speak for themselves and no response from Spectra either from an Amazon review or email.