Help!!!!Gas Seeping

[90growler]

My '90 YJ has been doing something very strange. The line that runs from the fuel tank near the exaust on the passenger side seeps when I turn the motor off. It is releiving pressure from that spot and then it stops. Prior to this happening you could hear bubbles being blown in the tank. It worsens when the tank is full. Since I bought it in Nov. fuel vapor can be detected at random times while driving or especially after being operated. The TBI system is not under pressure when the vehicle is not operating. Does anybody have a diagram of how the emmissions lines should run from the gas tank? I found one of the lines totally disconnected with a screw in the end of it. I have no idea where it goes. Could the evap. canister be clogged?

My emmisions diagram:

 

[redrooster]

Which line is leaking on that diagram? Is it metal or rubber?
Actually the fuel system does maintain pressure when the Jeep is off.. at least for a little while. You should have an in tank fuel pump sending pressure through the main fuel line to the throttle body. It shouldn't leak gas regardless. The lines are normally rated for 150 to 250 psi (rubber, more for steel) and the pump puts out nowhere near that amount. Without further info I would say the leak in your line allows gas to seep when you are stopped because the flow is stopped. When you are going the flow is moving and it probably quits leaking (as bad anyway). When a fluid leaks out of any system, that leaking volume is replaced with air. The air may be circulating back through the system and making the bubbling sound in the tank. It would be more audible when full of gas, depending on the height of the return line in the tank.
With that scenario of air in the fuel lines though, I would expect you to say the engine was stuttering also.

 

[90growler]

no stuttering and this is not the main fuel line that I am talking about. It is running fine. I am going to try and replace the leaking line. I am unsure what the disconnected line are or where they go to. I don't have a diagram on how they are supposed to be routed.

 

[redrooster]

Pull a diagram of the fuel tank and see if you can tell which one it is that is leaking. Then you can look at this diagram and see where it goes.

 

[90growler]

where do I get such a diagram? I have a repair manual but it doesn't have one for some reason.

 

[redrooster]

Look in the area where it tells how to replace the sending unit or fuel pump. There may not be a diagram, but it might tell you what line is what.
If your state doesn't require the emissions equipment then you may consider taking it off altogether.

 

[90growler]

Once I removed the rubber housing behind the rear passenger wheel I discovered a valve laying the mud that had collected behind the housing. The vave went to the top of a metal tube that connects two lines from the fuel tank and the evaporation canister. It turns out that the line to the evap canister was never connected to this valve in the first place. Fuel was spurting out of the line where the valve should be causing the strong odor and leakage. I called the dealer because nobody knew what it was at other parts stores. It's called a evaporation control valve in case anybody else runs into this problem....thanks for your help redrooster.

 

[redrooster]

Glad you got it fixed. Now you can smoke a celebratory cigar... in the cab!