Guest bastaad525 Posted December 21, 2003 Share Posted December 21, 2003 A couple quick questions. I seem to be having some issues with the vapor tank setup on my 240's still intact, stock fuel system in the back of the car... just recently I'm getting some serious fuel vapors in the cabin.. I did track down one, very very minor, leak, but the thing in general is I've just started questioning the whole setup. Do I HAVE to leave the vapor tank in place and hooked up?? Does the 280ZXT have a similiar setup? I dont remember having anything like this in my '80 N/A ZX, and if I can run w/o it I'll just pull the little thing out and block off the hoses going to it. Someone here suggested to me that if I remove or bypass the vapor tank that I wouldn't be able to fill as much fuel into the gas tank... seems odd to me... said he was only able to fill up 8 gallons after that. To be honest I wouldnt care if it got rid of this smell in the car.... I'm back to just parking the car for now... I can't drive it any more it literally makes me sick, so losing a few gallons of fuel tank capacity is an acceptable alternative.... Next question... as far as I can tell there are either two or three hoses running to that little tank... where do they all go? What are the possible 'malfunctions' of the vapor tank setup... what all can go wrong with it?? For anyone running an EFI setup with this stock fuel and vapor tank... have you ever had this problem: sometimes when I start the car I will hear a sound like high pressure spray coming from the filler neck... I'm not 100% sure but I believe it's fuel spraying into the filler neck from the little 1" or so opening that is immediately below the top of the neck... a few seconds after this sound stops the car will start to reek of fuel... very very annoying. What is causing this?? Needless to say it never did this when I was running an N/A motor with SU's. Where is this fuel coming from? And last question, and the one I need answered most of all... I found one little leak, I believe this one is possibly THE source of the gas fume smell in the car... there is a hose that enters the car from below, not sure where it comes from, but it enters the car right in front of the drivers side tail light cluster. It looks like about a 3/4" hose. It runs from there over to the passenger side... not 100% positive but it looks like it goes into the vapor tank. Now my question is... inline of this hose there is what looks like a small, brass colored PCV valve. Is this thing SUPPOSED to be there?? It doesnt' LOOK like it is... just like a PCV valve one side of it is threaded... of course it's that side that is leaking... you dont stick threaded ends of anything into a hose... no clamp on earth will guarantee a good seal. I dont see any mention of this thing in the haynes manual... I'm thinking of either just replacing the two hose sections with one long hose or in the meantime just replacing the PCV thing with a small section of pipe (can I use plastic/PVC or does it have to be metal?). Oh and please no one suggest to me to 'just get a fuel cell' if I had the money or time to put one of those in my car I'd already have paid someone to solve this problem for me Quote Link to comment Share on other sites More sharing options...
David K Posted December 21, 2003 Share Posted December 21, 2003 Oh and please no one suggest to me to 'just get a fuel cell' if I had the money or time to put one of those in my car I'd already have paid someone to solve this problem for me Well not a fuel cell, but get yourself a 280z gas tank Quote Link to comment Share on other sites More sharing options...
rags Posted December 21, 2003 Share Posted December 21, 2003 The hose you are talking about is indeed a gas tank breather hose and is connected to the vapor tank. I would start by dropping the tank and making sure there are no cracks in any of the tank breather hoses. On a 240 tank I believe there are three such hoses. The thing that has me puzzled is the sound of squirting gas you are hearing back by the vapor tank. HAve you by chance plugged the gas tank breather tube that runs to the engine compartment? It would be the metal line that comes up frm the frame rail and conected to the "T" fitting close to the coil. This is where it is on a 240. Anothere thing to look at is the vapor tank itself. Do you have a plastic tank or a metal tank? The plastic ones have been known to crack. Joe [Edit] Oh yeah, do as David said, get a 75 or 76 gas tank. They are designed to work with FI. Quote Link to comment Share on other sites More sharing options...
Jersey Posted December 21, 2003 Share Posted December 21, 2003 I used a '75 tank as well. Here's a shot of the RT - Quote Link to comment Share on other sites More sharing options...
fl327 Posted December 22, 2003 Share Posted December 22, 2003 I would just get a 75-6 gastank and be done with it. Fuel cells are good and the initial buy is cheap enough, but theres a lot of other work involved and in the end a lot of stuff changes, which isnt a bad thing, but to me its one of the reasons I went with a 280. I know some of the 240turbos just used the drain plug as a return, and yes it does work, but they have to watch out in turns anytime the tank is low, how low Im not sure. Another reason I went 280 this time around was teh exhaust/fuel smell, in my 240 I just couldnt get rid of it no matter what I tried, and I had a v8 in the sucker with 10-1cr just pumping the exhaust into my car. There were times I had to stop the car and get out of the thing, my clothes would smell like gas sometimes! My buddy has a 240zturbo with a ton of mods and 3.7 lsd, and the man cant even get a proper doughnut going because about 3/4 through the first come around, his car will want to stall out on him. He also cant 4wheel it around a turn because of this, or really pitch it hard at all just because of the fear of leaning out his very well built setup. It brings tears to my eyes I bought the man a 75 gastank because he's my boy and I couldnt stand all that proper equipment going to waste like that, besides, when that guy gets faster, I get faster.... Quote Link to comment Share on other sites More sharing options...
240hoke Posted December 22, 2003 Share Posted December 22, 2003 i got rid of the entire vapor system in my car. i just JB welde the holes that i didnt want to use on the tank and ran vents to the outside. Worked fine for me Ive got a new tank now though with all the holes soldered shut and a modified pickup for EFI, getting ready to put it in this week. 280z gas tank is really the way to go though -Austin Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 22, 2003 Share Posted December 22, 2003 So if I run a 280 tank, which wont be cheap either, that will eliminate the need for the vapor tank? If not, in what way does running the 280 tank help cut down on fumes in the car? I've had no problems thus far with the 240 tank as far as fuel cutout, I always keep it above a quarter and have taken some hard turns in it and never had a problem. I was also reluctant to swap to the 280 tank because I had not even a year earlier dropped the 240 tank and had it cleaned and recoated... so if it's just the issue of fuel cut out, I'd rather do something like get a surge tank. However if installing the 280 will somehow help this fume problem then I"ll have to look back into doing that. By the way the pic it jerseys setup is exactly how mine is (right down to the color of his paint!)... I will take a look at the breather tube that runs to the engine compartment today... I know it's not connected to anything now, I think it's just open... not sure about that though... I'll make sure it's not plugged up. And I"m really baffled as to why someone installed a one way valve inline with one of the breather hoses... gonna get rid of that thing today too and just replace it with a short section of pipe. Not sure when I'll get a chance to drop the tank and check the hoses, but I've inspected the sections of hose that are inside of the cabin and though old, none of them have any cracking that I can see. I'll pull that cover off of the vapor tank and see if the tank itself is cracked. Now that I know a bit more about how the whole thing works... I'm even more baffled by the squirting sound followed by the extremely bad fuel smell... none of those lines are supposed to carry liquid fuel... Also... this makes it even more interesting that I noticed wet fuel leaking around that PCV valve that's not supposed to be there... getting weirder and weirder. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 22, 2003 Share Posted December 22, 2003 Okay, replaced a couple of the hoses coming off the vapor tank. I found the little metal vent line that runs to the front of the car, below the coil, it's just open to air, and the splitter thing there is not there... not sure what to call that thing but apparently it's supposed to split the fumes between the intake and block. I checked the end and as far as I can see it's not clogged or anything. The two hoses I am not able to replace are the hose that runs to that metal vent line... and one of the big ones going to the fuel tank, which as far as I can see is not cracked or anything. Hopefully this gets rid of the fuel smell in the car. Oddly enough as I removed some of the hoses liquid fuel did come pouring out... I wasn't expecting that. The vent tank itself is metal, and looks fine. Quote Link to comment Share on other sites More sharing options...
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