Need help with a fuel leak from underneath rear of Pathfinder

[StevoDevo]

Just this morning my 2002 Pathfinder started leaking gas - it's dripping out of the rear right underside of the car and has been dripping away for hours. I opened the fuel filler cap and heard a gurgling noise and then fuel came up the tube and out of the filler hose (I quickly put the cap back on again)!

Any ideas what I can do?

[VStar650CL]

There are a bunch of things that can cause pressure and overflow from the tank. Here's a generic plumbing diagram from a '98~'02 bulletin:

Anything that clogs the path from the tank to the purge valve can cause a backup, and not everything will cause codes. Plugged ORVR plumbing can also cause it, but check that only if the vehicle is hard to fill along with the pressure issue. The most common problems on something that age will be a flooded/full evap canister or a mechanically-stuck vent control valve.

[StevoDevo]

Thanks so much. Should I take the gas cap off and let the fuel run out to relieve the pressure in there?

How can I determine where the blockage is?

[VStar650CL]

Thanks so much. Should I take the gas cap off and let the fuel run out to relieve the pressure in there?

How can I determine where the blockage is?

You're most welcome. Yah, let the pressure out the filler so you don't get sprayed with pressurized fuel underneath while doing diag later. Having that happen while you're flat on your back can be exceedingly unpleasant. For the evap canister, simply take it loose and see if it sloshes or liquid comes out. Weigh it if it doesn't, there's a spec weight listed in the ESM. If it's too heavy or leaks or sloshes, it's full and needs to be replaced. You can check the vent valve while it's out, just put 12V across the terminals (either direction, it's a solenoid) and blow through it. If you don't find anything there, start taking tubes loose at both ends and blow through them, and also make sure nothing is kinked. The Vacuum Cut and Vacuum Cut Bypass valves are less likely to cause this sort of issue, but if you need to diagnose them, the bulletin that the diagram came from tells how. It's NTB02-033, you can view it here:

http://www.lyberty.com/car/Maxima_A32_d ... 02-033.pdf

[VStar650CL]

PS - If you happen to find any black "beads" kicking around in the plumbing, then the charcoal bag inside the evap canister is broken and all the plumbing from the canister to the engine will need to be taken loose and blown clear. Loose charcoal usually plugs the Purge valve and makes a big mess, but there's no easy way to fix it, the plumbing has to be cleaned out from end-to-end including all the valves.