1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

2 vent tubes on gas tank?

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Old 05-09-08, 09:23 PM
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2 vent tubes on gas tank?

I tried searching.

There are the three tubes that come out of the gas tank, and then a fourth that goes into the frame. Where in the hell does that go? Is it just a vent to get fumes away from the exhaust? If so how long does it need to be since it tore when i dropped the tank.
Old 05-10-08, 03:44 AM
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Rusty-
here you go: 79/80 SA parts book diagram showing line layout. MY 80 RX7 had all FOUR lines coming off the tank, BTW. Because the detail of the TANK hook up is so vague, I had to draw myself a diagram, which is what you see on the UPPER LEFT corner of the pic.
(I dropped and cleaned my tank last summer).
Looking at the smaller diagram with the A-D labels, this is where I recall these lines going: NOTE "my" A-D does NOT coincide with the Page's A-D!!!
A- is an emissions recovery line that goes to the FRONT (one of THREE that ultimately do) - not it, nor ANY of these "vent" off somewhere away from the tank, as you suggest - they all attach to a hardline or the valve around the fuel pump
B- goes to the Fuel Cut Valve (stops fuel flow to engine if car is rolled)
C- goes TO the fuel pump
D- fuel return FROM carb (you'll notice TWO lines attached to the carb...)

If you dropped the tank to de-rust/gunk - I took mine to a Rad shop: they chem dunked and cleaned it out for $65, then I bought POR (.com)'s Gas Tank Seal Kit to re-seal the insides...
'Luck
Stu Aull
80GS
Alaska
Attached Thumbnails 2 vent tubes on gas tank?-rx-fuel-lines-.jpg  
Old 05-10-08, 02:30 PM
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Thanks 7aull, its hard having the redheaded step child of the RX7s.


To clarify it in my head.

45715 does what?
Is it 1/4 in. innerdiameter fuel hose?
Did you buy and install a check valve for B? where does it go from there?

I checked it out and I think you did it wrong. But it still works. I would get the pictures but I don't have the card reader where the car is. I think they are both vents, B and A on your sheet. I can see where the three metal tubes end up going, but not the rubber into the frame.
Old 05-10-08, 03:16 PM
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Does yours look like this? The plastic thing is a vent. I think there are three other fittings on the tank but it's hard to see in the picture.
Old 05-12-08, 03:07 PM
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Yea, thats exactly what mine looks like, just not as nice. It's gone for the dip today. Cleaned out the lines, new hoses, and fixed my power windows, pretty productive day. It's beer time now.

Do I really need the foam?
Old 05-13-08, 04:19 AM
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Hi Rusty-
You say mine is wrong? Hmm. works OK, and I had another SA to confirm it against so...
Foam: yeah unless you want the tank to bang against your spare wheel well!!

Also - I reused the check valve, but replaced all the lines - don't recall diameter, but took a piece in with me to the local parts store, no prob matching up.

re: 45715 - I think this is the one that "T's" off the check valve into the body frame beside it (so it must vent in there as you suggested).
Stu Aull
80GS
Alaska
Old 05-13-08, 04:29 AM
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Rusty
you asked "Did you buy and install a check valve for B? where does it go from there?"
as the OEM diagram shows:
fuel comes from tank:
->via C hose (on MY diagram)
-> to fuel filter-
->to fuel pump-
-> Thru "A" ON OEM DIAGRAM!
-> into check valve ("45160")
-> to carb
Hope this helps. I know at the time it confused me no end!!
Stu Aull
80GS
Alaska
Old 04-27-17, 05:58 PM
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Originally Posted by Jeff20B
Does yours look like this? The plastic thing is a vent. I think there are three other fittings on the tank but it's hard to see in the picture.
Resurrection.

I'm installing an SA fuel tank into an FB and cannot figure out where that vent hose would connect. I appreciate the help in advance.
Old 04-28-17, 01:14 PM
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found this thread but still not clear as to what to do with the fuel vapor valve line.

https://www.rx7club.com/1st-generati...k-help-941997/

Should it just be capped and get a vented cap?

"The rear most one goes to a fitting in a rubber gasket and thats the vent line. If you cap it off get a vented gas cap."
Old 04-29-17, 10:25 AM
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The 1985 tank can be seen here with each line identified.

http://foxed.ca/rx7manual/manuals/19...ssions_12A.pdf
Old 04-29-17, 01:00 PM
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Originally Posted by KansasCityREPU
The 1985 tank can be seen here with each line identified.

http://foxed.ca/rx7manual/manuals/19...ssions_12A.pdf
Thanks for your reply, I don't have any issues with where to connect the feed, return, and vent hoses. Its the fourth, fuel vapor valve, on top w the plastic swivel that I cannot figure out where to connect it to?
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