Gas fume small near evap canister on '95 Grand Am

[WS6FirebirdTA00]

I have been smelling gas fumes for a while after (randomly) running the AC but every time I stopped the car it seemed to go away. This time I finally caught it I believe. As I sniffed around under the hood, the smell got quite strong right at the evap canister.

I was not able to pull the reservoir off to check it out, but did inspect the lines which looked fine. Question is, other than an obvious crack or something, what else could cause this and is there a common issue/fix?

I don't know if it could be related or not, but sometimes after the car has been shut off, sits a little, and restarted it seems to hesitate for the first little bit. If I give it gas, it is like it does not want to respond or breaks up. Normally after the first two stops in my neighborhood it will clear out and act fine, or if I give it more throttle.

It also seems my gas mileage back and forth to work is down. I used to get ~26-27 MPG in summer, now I may be lucky to see 25-26, but normally is ~24.

[WS6FirebirdTA00]

Any help?

It seems it is coming out of the vent. There are two lines that are on there and then a 3rd opening with a vented cap over it. When I shut the car off you can see the fumes come out and if I put my thumb over it, it will pressurize. Not sure if this is a canister issue, vent solenoid issue, or something else.

[bszopi]

I'd offer some help, but I've never have to mess with the evap system, so I had no reason to study its operation. Sorry...

[60dgrzbelow0]

This is one of those problems that deserves a look see from a professional automotive technician because of the the very real chance of a car fire. The engine evaporator is designed to contain mostly unburned vapors and prevent them from contaminating the environment as condensed fuel dripping on the ground. Any fuel that is not burned via normal combustion is generally vaporized and dealt with in the super-heated catalytic converter. You simply cannot put yourself and your family at risk of being trapped in a vehicle with a fully involved fire under the hood being fed by multiple pressurized fuel lines. Unless you can pinpoint this problem as a cracked evap canister or loose fuel line fittings yourself (and soon)... Take your vehicle to a local reputable shop (Google and scan your local "Angie's List" for potentials) and ask them to carefully inspect your fuel system. We already know that you are smart enough to deal with any mechanic who might mistakenly play upon your fears of fire... because you are here now trying to work this serious issue out. Let a Pro go through things for a reasonable fee and give you some peace of mind... Best of Luck with this!

[Azrael]

Our evap systems purge vapours into the engine to be burnt in regular combustion and not in the cat. convertor. These vapours originate from the gas tank so it sounds like the system is pulling in liquid gas for some reason (Purge solenoid stuck open?). The pressurization is likely from the liquid gas evaporating in the cannister, same principle as a pressure cooker but at a much lower temperature. I can't recall if the evap system purges at startup or after the engine warms up. This system was mandated by the EPA so there should be more accurate info on how these systems work on the net somewhere.

[60dgrzbelow0]

...and just in case the FPR is also acting up at the same time...

http://www.youtube.com/watch?v=UHTV3W5VI5w&feature=related

[WS6FirebirdTA00]

I don't take my cars to a shop, I was hoping to get some insight on here from someone with the same issue until I had time to troubleshoot it this week. I know about vapors and all that, so I vented the line outside where it would not be an issue and also did not park the car in a closed areas. A lot of people do EVAP deletes and old cars also vented to atmosphere. You bring up a good point for those uneducated though. I appreciate your concern. I also drive around with a fire extinguisher in my cars. Came in handy when I was running at the track one day and the guy I raced blew up and caught fire.

I finally got some time to check it out yesterday. Since the evap pulls in fresh air through the canister and the vacuum through the canister draws the vapors from the tank, the first place I figured I would start would be the line. Nothing was crimped or pulled off. I then moved to the solenoid. I was checking for high coil resistance but found the coil was open loop (or at least a high enough resistance that it was out of range of my multimeter). Incase I missed something, I tried to power it. Nothing. I got a new coil, resistance was good around 110 ohms. I powered it up and it would activate the coil. After this I went for a short drive to cycle the purge system and everything worked well. It evacuated the charcoal canister and now relieves pressure nicely. Figured I would post up for those with similar issues.

Thanks for the help.