The vent line from the fuel fill neck to the tank should provide the necessary ventilation while filling. I doubt your EVAP purge valve was the cause of your filling issue for the very reason you state. It is closed when unpowered. I would check out the vent line from the filler neck to the tank to see if it is somehow plugged.

 

Thanks for the reply Swartlkk. I am a little uncertain what you mean when you say the "vent line from the filler neck." Correct me if I'm wrong here: The filler neck is a solid thick rubber hose that's a straight shot into the tank. Directly to the left of this is a connector (I think its the vent). This line appears to run to the ASM canister behind the left rear tire. From the ASM canister a line runs into the valve that I described was stuck closed (the vapor canister purge valve http://info.rockauto.com/ACDelco/Det...ml?214-633.jpg ). I disconnected all of these lines and there appears to be no obstruction. The only thing I DO know is that opening up that valve allowed me to fill up. Because no power closes the valve, this is very puzzling to me.

 

There are two lines running to your tank (at least there should be) from the tank up to the filler neck. One is rather large (2" to 2-1/2") and one is smaller (1/2" to 3/4").

For a 4dr both lines run up and over the frame:


A generic view showing the two lines:


It is that smaller line that is responsible for venting the tank while you fill it.

 

Are you sure those images are for a 2002 4dr? I can clearly see where there is a vent line and filler hose. The vent line appears to come off the filler neck and go where? Is there a valve at the end of that line or it goes right back into the tank? The image is not very clear. I'm pretty sure my tank does not have a nozzle to the left of the filler hose. I will try to snap an image of the tank next time I am under the vehicle.

 

The first image is applicable to your vehicle.

 

Where is that purge valve located?

My o 02 does the same thing and it's annoying beyond belief!

So, the vent solonoid on my 02 blazer is nothing more than a solonoid with an electrical plug on it. Shouldn't there be at least a hose from the fuel tank on it? It's just snapped into place with no hoses hooked to it! The tank won't fill easily at the gas station causing me to look in this direction.

 

Purge valve is on the engine.

The vent solenoid should have a 3/4" or so rubber hose connected to it on one side. Search on "vent+solenoid" for further information with images, etc.

 

Thanks much, can do.