View Full Version : Fuel Evaporation Canister/Check Valve Problems???

James West
07-05-2006, 02:39 PM

Last fall, I nearly filled my '87 GN gas tank with gas and noticed during storage that there was a faint smell of fuel when I would open the door to the garage. I know it was coming from the GN and not the other cars because the fuel in the tank was 100 onctane unleaded and it has that distinctive smell to it.

My question is when I uncovered the car this spring and went to start it, the gauge showed just above 1/2 full and I had nearly filled it last fall. I perfromed an inspection of the entire fuel system from front to back and can not find any fuel leaks anywhere on the entire fuel system. the sniff test is pointing to the fuel evap/recurc canister.

Is there a possibility that the solenoid is bad, possibly stuck open OR is there a possible problem with the in-line check valves in the system possibly being reversed? Why I say reversed is because I was chasing a high BLM problem last year and had the check valve out. What is the correct configuration of the check valve? Gray end to the front, black end to the back or reversed?

Also I have no codes set/stored or showing on T-Link.

Any ideas would be greatly appreciated.

Best Regards,

James West
Omaha, NE.

07-06-2006, 10:32 AM
I wouldn't think that you would lose that much fuel through the canister in that period of time. The canister is basically "open" to the atmosphere anyway (there is a filter on the bottom of it), so even if your solenoid was stuck open, which is unlikely, there is already a path open for vapors to escape (thru the canister). There is also a restriction in the vapor line coming from the tank further limiting evaporation thru the system. Also, it is normal to smell a little vapor around the canister area.
I know you did an inspection already, but I would look at the tank again closely. I am wondering of there is something going on at the top of the tank that is not readily visible. Maybe the seal for the fuel pump/sending unit or a cracked hose?
Did you confirm that it actually had a half tank in it by refilling the tank?
Finally..I don't think this is your problem because you haven't been driving the car, but one time I had liquid fuel, not vapors pouring from the bottom of my cannister (engine running). The problem ended up being a loose clamp at the fuel pump which was allowing fuel to spray directly into the opening for the vapor line leading to the canister.
Hope you find it and it's easy to fix. Steve