Heres the background. Car used to be 318/904 2bbl and I never had any issues. Then I switched to a 360/904 4bbl and thats when it started. When driving there is a fuel/fume smell inside the car and its very noticable, and starts to bother me when Im in the car for long rides, especially around town when I cant get a high volume of air flowing into the car.

There are two lines that come up towards the motor on the passenger side of the engine bay. One is the fuel line that runs from the fuel sender/fuel pump. The other, which also follows the fuel line from the tank, is what some people called a vapor line for emissions. They said it was definately not a fuel return line. Does it allow the fuel tank to vent properly, and not cause it to create a vacuum in the tank causing fuel starvation? Because when I go to refill my tank now there is a very noticable swoosh of air when I remove the gas cap, enough that it startled me the first time. Also, when I park the car, I can walk back into the garage and Im overpowered by the smell of gas/fumes. I even put on a brand new vented gas cap to rule that out since the one I had was so old, it had no effect.

My new carb, eddie 1406 does not a fitting for this vapor line? I have it blocked off right now, is this my problem. Should I just leave it open? Should it be hooked to a breather tube, or air cleaner?


roe

What year and model?

sorry. sig car, '71 satellite

Does it have the VS in the trunk and is it hooked up to the four hoses to the gas tank?

No not in trunk. It appears to be mounted in the wheelwell on the driverside rear. The four hoses leave the driver side of the tank and tuck up into the wheelwell, and there is a panel there that I can unbolt after I remove the rear tire. All 4 of the hoses are there and intact. Old, but don't seem to be cracked/leaking, and still feel flexible when I wiggled them. It just seems to have started after the carb switch, now that that secomd line I mentioned is not used.

THESE type O gas fumes ? ...

Chally_1 must be close to the car ! ..

Now that I think about it, I belive that second line usedto be connected to a small nipple on the valvecover breather when I had the 2bbl carbon and air cleaner. But I can't remember for sure. When I swapped on the 4bbl I had to change the air cleaner, which also made me put on one of those breathers that's just a filter. I stillhave that breather I believe, but can'tremember for sure if that's how it was hooked up. Whadaya think?

Hay roe ... he is the GASyEST guy on this board ..

In 71 they didn't use a charcoal canister they vented the fumes into the crankcase by the vent lines connected to the breather. If that tube isn't connected then it may be venting to the engine compartment and that is what you are smelling.

Adding a charcoal cannister is safer as the fumes in the crankcase sometimes ignited popping valvecovers and such. In 72 the factory started using the charcoal cannisters and has ever since.

That second line coming up to the engine needs to be connected to the valve cover breather and a functioning PCV system with solve your problem. It vents the tank and everytime you start your car it'll suck any fumes into your engine and you will never smell it.

Make sure nothing is leaking in back and all connected.

Ok, PCV valve is on and functioning on the driver side. I just put a new one on with the last tuneup. I still have the original style breather so I will give that a shot first, and I'll probably relpace the vapor seperator and hoses to it while Im at it. I'll report back with results

Thanks guys.
roe

Where can I find a fuel vapor seperator? I saw nothing on rockauto or autozones website. I'll try giving them a call tomorrow to see what rockauto says.

Seems to be a theme today!!! I just got great pics and info on this exact subject. From what I saw, the vapor seperator can't wear out, and if all lines are hooked up and good, I'd plumb the vent line that is disconnected to the PCV and see if that did it before I started adding and throwing parts at it. just my

Yeah, I looked at that thread as well, didn't want to throw off what the OP was looking for so I started this one. I will definately examine mine for any rust holes or anything like that, replace my rubber hoses going to the vapor seperator, and reconnect my vent line to the breather and go from there.

Here is the pic of the spare valvecover breathers. I tried the one that has only one nipple on it, and connected the vent line to it. It actually made the car run worse. Stumbling at idle like it wanted to die on me. Took it back loose and left the vent tube hanging open and it ran smooth again.

Here is the pic of the vent tube, the one that has the white tape strip on it in the bottom left. The tube ends pretty much where u see the tape. Also, you can see the style of valvecover breather Im running.

Here you can see where my PCV valve is hooked up. it runs from the breather to vacuum port on the front of the carb. It has a strip of yellow tape on it.

So should I hook the vent tube to a T into the line that has the PCV valve on it? If so, looking at the pic, should it be connected to the left of the PCV valve, or to the right of it?

The breather with the multiple nipples is the one that was on with the 2bbl carb. One nipple connected to the air cleaner, dont remember what each port went to.

Another random thought that I dont know whether its correct or not, is if my PCV valve may have been T'd into the vac line for the brake booster.

roe
What do you guys think I should try next?