97 240 SE EVAP system

[240sxGT]

I have read the posts on removing the evap stuff up front in the engine bay, but I have not seen anyhting about removing the evap stuff in the rear,behind rear bumper on passenger side. Can I remove this stuff as well. Asked this a while back in 240tech but no response. Please helpThanksJames

[NISTECH]

Does Ohio not have an emissions inspection? If it does you will set a check engine light and/or your moniters for SRT wont complete with out the equipment. There is one line from the engine bay that goes back to the canister under the car. If you undo that line at the intake manifold you need to plug it off or you will have a huge vaccum leak. Secondly you can pull every bit of it off at the rear [ assuming you dont have the emissions inspection problem I mentioned] There will only be one port you need to plug on the fuel tank when your done. The things you will find in the back of the car are The canister which has 3 ports on it for hoses. The largest hose is the vent hose. You can remove the hose and everything it attaches to. not much there. The second largest is the fuel tank hose it goes from the canister to a fuel cut valve [rollover valve] which also incorperates a fuel cut solonoid valve. Then goes to the tank. Everything between the canister and the tank can be removed but you must plug the port on the tank or you will leak fuel. The smallest line is from the engine bay. That is the vaccum line you disconnected at the engine. about 3 to 4 inches of hose come off the canister that attaches to a evap pressure sensor via a "T" in the line. you can remove that as well. If your really feeling ambisious[sp?] you can remove the steel line that goes from the engine bay to the rubber hose leading to the "T" at the pressure sensor.

Now keep in mind the things you do to this system will set a list of codes. P04xx codes galore will come up. like p0446 vent control valve , and another code for fuel cut solonoid valve , evap pressure sensor, evap purge solonoid valve, Ect ect. IF your ok with all that have at it rip it off , it will net you about a 3lb weight reduction.

With that said here lies your problem. when you plug of that vent to the tank going to the evap canister your tank has no way to breath properly. You tank will expand and collapse with tempo changes as the fuel vaporizes due to heat and condensates with lower temps. This can bring on fuel starvation problems or refill problem when putting fuel in the tank. The canister is there to allow the tank to breath yet trap precious fuel vapors which can be used by the engine during purging which helps a little in the fuel economy dept. The canister has a fuel vapor absorbant charcoal in it so as the tank pressure expands from the fuel returning to the tank from the engine heats it up the pressure is pushed through the canister and out the vent off the canister. Any vapors are trapped in the charcoal and at cruise the vapor is allowed to enter the engine. The o2 sensor senses the richer mixture and cuts back the injector pulse to lean it back down. Now the engine is using fuel vapor as part of its mixture, fuel vapor that would othewise be vented to atmosphere if it werent for the canister being there.

Removing the fuel cap would alleviate the feul starvation problem however your fuel vapor loss would be accelerated since you have given it a much larger hole to vent out.

[240sxGT]

Thanks NISTECH that was great. We did have an emmisons inspection but it ended Jan. 1.Thanks again.