Datsun_Z240 Posted January 31, 2013 Share Posted January 31, 2013 So i removed all the evap related hardware on my 72 240z and am now left with a stock gas tank with a lot of extra ports. I have searched and searched, and have found very little info as far as which ports to plug and which to keep. Although there is no evap hardware left so logically you would plug all the holes, but that would mean little to no gas tank ventilation. So now im at the point trying to figure out exactly what to plug, what to leave, or how to vent. Any help would be appreciated! Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 31, 2013 Share Posted January 31, 2013 Here's a little... Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted January 31, 2013 Share Posted January 31, 2013 Ive heard of guys plugging and the downside is that gas will spew when it gets too hot or when you try to get close to filling the tank. If your big vent hose is not in operable condition, I suggest getting the vent line from NAPA auto, make sure you get sufficient length so you can route a long way without kinking. Quote Link to comment Share on other sites More sharing options...
JCan Posted January 31, 2013 Share Posted January 31, 2013 Are you sure you want to remove the evap tank? I know the hoses are a pain in the butt, however I was able to replace all of them with hoses from Napa. 1/4 " for the return hose, 3/8" for the fuel pick up and one vent hose, 1/2" from the far end of the gas tank to the vent tank, 5/8" - gas tank to the vent tank, and 3/4" from the gas tank filler tube. Here is what a fellow Z driver says.. "If you remove the vent tank and plug the outlets on your fuel tank, you'll never be able to fully fill your fuel tank. The air that gets displaced by fuel when you fill the tank has to go somewhere. With the vent lines plugged, that air gets trapped in the tank limiting the amount of fuel you can put in. You'd probably only be able to fill the tank about 3/4 full max. Also, even if you did manage to fill the tank, enough pressure could build up to force fuel out the filler neck and down the side of your car!!! I've seen it happen." If you still want to remove the evap tank, I'll try to find a copy of how to do it for you. ( I saw it somewhere on the web) Jim Quote Link to comment Share on other sites More sharing options...
Datsun_Z240 Posted February 1, 2013 Author Share Posted February 1, 2013 Unfortunately I not only already removed it but rushed and tossed it too. From the few results I found on the topic, seemed like it was doable, so I did it. Now I realize the issue. With that in mind, is there a way perhaps I can run the main vent hoses to a vented bottle or can of some sort? In a sense, make a home made evap tank? Or perhaps even a vent hose with a small filter on the end? Thanks again for the input everyone! Quote Link to comment Share on other sites More sharing options...
Dershum Posted February 1, 2013 Share Posted February 1, 2013 Couldn't one hypothetically run those three lines together into a single line, and then vent it to the top vent tube on the fuel filler tube? That would solve the problem of not allowing the tank to fill all the way. Then replace the gas cap with a vented cap so you don't get a vapor lock in the tank while the car is running? The only problem I can see with it is possible fumes into the car from the vented gas cap. I don't recall how "sealed" the gas cap area is, so the fumes vented through the cap could possibly get into the cabin of the car. Again, this is just theory, but I seem to recall reading something to this effect a while back, and I've been trying to think through how to eliminate the vent line that goes forward into the engine compartment from the vapor canister so I don't have to run that extra line. I seem to recall someone mentioning that it could be connected to a coiled line that as long as it was higher than the tank, it could be safely vented to the atmosphere under the body of the car. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted February 1, 2013 Share Posted February 1, 2013 We removed the evap tank on our '73. We closed all but the highest vent line on the tank. From this vent we ran a line to the vent at the filler neck. Here we made a tee fitting and connected the tank vent to the filler neck vent. The third leg of the tee has a hose that goes up and over the feller neck and then drops down and exits the cabin through the floor of the car to the outside, ending near the fuel gauge sender. It seems to work well and we can fill the tank completely and easily. It does seem to smell a bit when the tank is full but I do not see any fuel leaks. Quote Link to comment Share on other sites More sharing options...
morbias Posted February 1, 2013 Share Posted February 1, 2013 Over here in the UK we didn't get the evap tank. With reference to the picture posted above, the following can be plugged (if you want it set up like a UK system): 6 and 14. If I remember right, there is a T-section fitting in hose 3 that hose 5 connects up to, and the end of hose 3 points down and exits through the chassis right next to where the fuel filler pipe exits the inside of the car. Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 1, 2013 Share Posted February 1, 2013 So i removed all the evap related hardware on my 72 240z and am now left with a stock gas tank with a lot of extra ports. I have searched and searched, and have found very little info as far as which ports to plug and which to keep. Although there is no evap hardware left so logically you would plug all the holes, but that would mean little to no gas tank ventilation. So now im at the point trying to figure out exactly what to plug, what to leave, or how to vent. Any help would be appreciated! Really? http://forums.hybridz.org/topic/110485-bcbroncos-surge-tank-install-and-use/ Quote Link to comment Share on other sites More sharing options...
JCan Posted February 1, 2013 Share Posted February 1, 2013 Datsun_Z240: It looks like you have lots of options. I would like to suggest one additional! you can purchase a gas vent tank from the internet (ebay, craigslist) (here's one for $34 http://www.ebay.com/itm/70-78-DATSUN-240Z-260Z-280Z-FUEL-VAPOR-TANK-WITH-SCREWS-GAS-BOMBA-/321043465435?pt=Motors_Car_Truck_Parts_Accessories&hash=item4abfae84db&vxp=mtr ) and then purchase gas line (be sure it is rated for gasoline (go to napa (hose sizes above))) for another $60. When you run the lines, be sure there is no way for air to travel between the outside and inside cabin where the lines cross interior to exterior, rubber grommets maybe if you use the old ones you could add silicone to take up the slack between the hose and the rubber. It is a lot of work, but once it's complete, you should have no problems for the next 10-20 years! Good luck with which ever you decide to do! Jim Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 2, 2013 Share Posted February 2, 2013 I won't dredge up the detailed post on the 510 Wagon EVAP Delete...but the vapor phase recovery tank on that car was missing also so I was forced by expedience to come up with deletion alternative. I first converted the larger 15mm vent lines to 3/8" using similar style Nylon Adapters as Nissan used for coupling hoses. Then when they were all up to where the old tank was, they got manifolded together on a log I made from brass piping "T" fittings. The tank held 5psi for 24 hours without leakdown. The only thing I did afterwards was make sure not to fill all the way to the top if I wasn't driving off on a long trip. Without the vapor-phase tank, there really isn't any expansion alternative for the gasoline. It will either go up the filler neck, or (more likely) in liquid form travel forward in the vapor line and puke directly into the crankcase, or air cleaner. I've replaced the EVAP cannister in some 260's with one from a Geo Metro. I've toyed with the idea of putting the entire EVAP system, charcoal canister and all in the back of the car near the tank... One or two lines front to back should do it... Would make updating a smelly old 240 to modern captive emissions (no smell in the garage after shutdown) capabilities. Quote Link to comment Share on other sites More sharing options...
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