2005 GMC Savana Gas Fill Problem

check the evap canister for excessive fuel,pull the lines off and see if gas pours out,if you over fill the tank the gas goes into the canister and vapor locks the gas tank.post back with what you find.

Where is the evap canister?

Thanks very much for your help. I'm having a little trouble with the orientation of the diagram you sent. Can you give me a little more help such as in what area to look?

the arrow on the diagram shows that is the front of the vehicle and its located on the frame under the drivers seat in front of the gas tank.

Here's what I've done so far.

rechecked the fill tube and made sure there were no kniks. Removed and inspected the vent tube, but could not determine if there was any obstruction down in the tube. Did not appear to be any kinks in the vent tube. Talked to a certified GMC service technician who thought the problem was a blockage in the vent tube. He did not indicate that there was a great problem if there was gasoline in the canister; said if there was I should just"pour it out". I couldn't get the canister off so am not sure about that either. Still have a problem

I would get the canister off,to make sure.a saturated canister will give a hard fill condition,any accumulation of gas in the canister is a bad thing,pouring out the gas will do nothing but bye you some time until it happens again.it this is how the evap sys works,The evaporative emission (EVAP) control system limits fuel vapors from escaping into the atmosphere. Fuel tank vapors are allowed to move from the fuel tank, due to pressure in the tank, through the vapor pipe, into the EVAP canister. Carbon in the canister absorbs and stores the fuel vapors. Excess pressure is vented through the vent line and EVAP vent solenoid valve to the atmosphere. The EVAP canister stores the fuel vapors until the engine is able to use them. At an appropriate time, the control module will command the EVAP purge solenoid valve ON, allowing engine vacuum to be applied to the EVAP canister. With the EVAP vent solenoid valve OFF, fresh air is drawn through the vent solenoid valve and the vent line to the EVAP canister. Fresh air is drawn through the canister, pulling fuel vapors from the carbon. The air/fuel vapor mixture continues through the EVAP purge pipe and EVAP purge solenoid valve into the intake manifold to be consumed during normal combustion. The control module uses several tests to determine if the EVAP system is leaking. if the canister is ok you could have a fuel tank pressure sensor problem or vent solenoid problem,I would have it scanned for dtc's and have the evap sys smoked for leaks or blockage.

I finally had to take it to my dealer (Behlman CARnection in St Peters, Mo). I had just recently bought the van and had the problem from day one. I should have taken it in sooner as they told me they would fix it; I just thought if it was something simple I wouldn't waste their time. Anyway, they took it in, gave me a car to drive while I waited and dropped the tank and found that the anti-spill, roll-over valve was stuck almost shut. They fixed it at no charge to me. They were super to work with.