Pizza is #3 the part your talking about? If so, its non existent on my car.

yes. plastic tanked cars suck..... ok so yeah your vent valve is part of the canister on top of the tank. might be able to get a look at it if you just lower it a bit. thats so shitty. glad i have a steel tanked car. evap can is near filler neck under plastic guard.

Ok so the evap can would be the rectangular unit next to that black hose on top of the tank? Also if that dump hose is the vent hose do you think I should just try and shoot some compressed air up it first? Or will it not do anything? I'm thinking its probably a one way valve but I could wrong.

Well I found this picture which shows what Im looking at pretty clearly.


http://i662.photobucket.com/albums/u...8/fueltank.png

I also found this little write up:

GENERAL - The Evaporative Emission (EVAP) Control system used on all vehicles is the charcoal canister storage method. This method transfers fuel vapor from the fuel tank to an activated carbon (charcoal) storage device (canister) to hold the vapors when the vehicle is not operating.

When the engine is operating, the fuel vapor is purged from the carbon element by intake air flow and consumed in the normal combustion process.



MORE IN DEPTH - The EVAP purge solenoid valve allows manifold vacuum to purge the canister. The Powertrain Control Module (PCM) supplies a ground to energize the EVAP purge solenoid valve (purge on). The EVAP purge solenoid control is Pulse Width Modulated (PWM) or turned on and off several times a second .

The EVAP canister purge PWM duty cycle varies according to the operating conditions determined by the mass air flow, the fuel trim, the engine coolant temperature, and the intake air temperature. For certain EVAP tests, the diagnostic will be disabled if the TP angle increases to above 75 percent . The evaporative leak detection diagnostic strategy is based on applying vacuum to the EVAP system and monitoring for vacuum decay.

The fuel level sensor input to the PCM is used to determine if the fuel level in the tank is correct to run the EVAP diagnostic tests. To ensure sufficient volume in the tank to begin the various diagnostic tests, the fuel level must be between 15 and 85 percent .

The PCM monitors the fuel tank pressure/vacuum level via the fuel tank pressure sensor input.

Maybe I should try replacing the evap purge solenoid valve since that's what purges the canister and its the easiest part to get to since its on the intake mani.

Damn, that's how the plastic tanks are set up? Sucks to be you. :haha: All of that stuff is within easy reach on the metal tanked cars. From that pic I'm guessing the white thing on the left is the tank vent.

Idk if it is or not, supposedly its supposed to vent into the canister and then the evap purge solenoid is supposed to purge the canister. Maybe the solenoid isn't working and the canister is fouled and can't take anymore

From what I can see in that pic and what I've seen on other gm makes the vent is the one just below the fillet tube with the red electrical plug and the one hose with the clamp. That the style vent valve I'm used to and was I. My truck. That's what vents the vapors

So your saying this is the vent?


http://i662.photobucket.com/albums/u...eltankspec.png

yeah ben is correct. thats the faulty valve. weird the steel tanked cars have a completely different setup. maybe the plastic tanks can collapse? so they added more safety measures?