pressure relief valve for the gas tank??

[linksys42]

Was wondering if anyone knew where the pressure relief valve for the gas tank is on a 99gst? On the other 2g’s its inline before the check valve right after the hard piping that come from the tank at the bottom of the firewall on the passenger side? But fore some reason on the 99’s there isn’t one there? Thanks

 

[Black_Bullet]

Why is there a benefitial way to remove it or something?

Not to thread jack but while the topic is up id like some info on the fuel pressure relief valve as well. I hear they kick in after x amount of fuel pressure has been reached what psi is that if anyone knows, and what happens when it does kick in? I know fuel pressure raises 1:1 with boost, and due to running a n/t fpr , my base fp starts at 47.6psi...
I doubt it would kick in unless im running excess of 30 psi ( which I doubt id ever be. )
But think it would be a good thing to know... Hopefully my questions will be relevant to the op in some kind of way as well. Thanks...

 

[oldman]

Why is there a benefitial way to remove it or something?

Not to thread jack but while the topic is up id like some info on the fuel pressure relief valve as well. I hear they kick in after x amount of fuel pressure has been reached what psi is that if anyone knows, and what happens when it does kick in? I know fuel pressure raises 1:1 with boost, and due to running a n/t fpr , my base fp starts at 47.6psi...
I doubt it would kick in unless im running excess of 30 psi ( which I doubt id ever be. )
But think it would be a good thing to know... Hopefully my questions will be relevant to the op in some kind of way as well. Thanks...

Tank pressure and fuel pressure are two different things.

Sorry OP, I don't know the answer to your question.

 

[Black_Bullet]

Tank pressure and fuel pressure are two different things.

Sorry OP, I don't know the answer to your question.

Oh ok, because I have heard of a fuel pressure relief valve which kicks in after a certain amount of fuel pressure. I dont even kno where the fp relief valve would be located so I assumed i was talking about something related to what he was talking about.. Sorry for the misunderstanding.

 

[luv2rallye]

From the 99 Mitsu Eclipse factory manual for FWD:

 

[linksys42]

Thanks luv2rallye, but the image is a little hard to see the vapor hose routing. I cannot make out which vapor hose feeds to the hard line that runs back to the engine bay for the EVAP system. Is the pressure relief valve located by or in one of the assembly’s on the fuel tank? The reason I ask is that I want to delete the EVAP system but I want to keep the proper pressure in the fuel tank. Thanks again for the image!

 

[DGajre777]

Thanks luv2rallye, but the image is a little hard to see the vapor hose routing. I cannot make out which vapor hose feeds to the hard line that runs back to the engine bay for the EVAP system. Is the pressure relief valve located by or in one of the assembly's on the fuel tank? The reason I ask is that I want to delete the EVAP system but I want to keep the proper pressure in the fuel tank. Thanks again for the image!

I think that you are making it more complicated than it is. Take out the entire charcoal canister unit and you'll see 2 hard lines. One of them goes to the tank and the other one comes from the tank. Plug them both up for about a day and then take one off. If you any gas fumes, then thats the one that you need to vent. If you unplug a line and you don't see any gas fumes, then it is the other one that you need to vent.

Where is your charcoal canister located? Is it under the battery or under the driver side headlight? If it is under the driver side headlight, the lines run near the stock coolant bottle and I can tell you exactly which metal line you need to vent.

 

[D_Eclipse9916]

and which one is that? The left or the right if your looking from driver's side to passenger side next to the stock location of the coolant bottle....

 

[DGajre777]

and which one is that? The left or the right if your looking from driver's side to passenger side next to the stock location of the coolant bottle....

Here is the pic and this only applies to 2Gs that have the charcoal canister located under the driver side headlight. From the 2 lines, plug the line towards the front of the car, and vent the line that towards the rear of the car. I installed a little metal filter on mine.

 

[linksys42]

I think that you are making it more complicated than it is. Take out the entire charcoal canister unit and you'll see 2 hard lines. One of them goes to the tank and the other one comes from the tank. Plug them both up for about a day and then take one off. If you any gas fumes, then thats the one that you need to vent. If you unplug a line and you don't see any gas fumes, then it is the other one that you need to vent.

Where is your charcoal canister located? Is it under the battery or under the driver side headlight? If it is under the driver side headlight, the lines run near the stock coolant bottle and I can tell you exactly which metal line you need to vent.

This is the problem; the 99gst doesn’t have a charcoal canister at all. And it doesn’t have the pressure relief valve (in the same location) for the gas tank as the other 2g’s. I know what line that needs to be vented I just need to know where the pressure relief valve is for the gas tank so the tank has the proper pressure and I don’t get a CEL? On all other 2g’s the pressure relief valve for the gas tank is right at the base of the firewall where the hard piping for the vapor fumes from the gas tank comes up into the engine bay. Thanks for all the help

 

[D_Eclipse9916]

Here is the pic and this only applies to 2Gs that have the charcoal canister located under the driver side headlight. From the 2 lines, plug the line towards the front of the car, and vent the line that towards the rear of the car. I installed a little metal filter on mine.

Just wondering whats happening if I have had both venting for a while.

 

[DGajre777]

Just wondering whats happening if I have had both venting for a while.

Nothing, as long as you don't plug up both lines, you'll be fine. I had both mine vented for a few weeks, but I wanted the return line plugged just incase anything happened to go in there.

 

[Nitilus]

I have a 96 GSX I believe that this is the vent tube that went to the charcoal can. So your saying to vent it to atmosphere? What would happen if it got capped? Is there potential for the tank to rupture? What if you used a spring loaded pressure relieve valve? Would that be better than just open? Need some help here . Thanks

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