chasing fuel vapor

[66forfun]

New fuel system front to rear including sending unit, filter, electric pump, reg, holley dual feed all connected with 8an hose and fittings. Bad fumes but no drips, I've checked the fittings with kleenex for seepage. Integral garage and these fumes don't mix well, are the gas analyzers that a home inspector would use sensitive to gasoline? Should I air test the lines under water? I am ready to use a lighter!

 

[D.Hearne]

Fumes are coming from the tank vent. Some cars had a separate vent, some were vented thru the filler cap. I don't recall which the Stangs were. If it is thru the cap, you can fix that by installing a tank vent and running a hose back up to the aircleaner, the fumes then will be captured in the aircleaner and sucked into the carb when you crank the engine.This is how I did it on my 89 V8 Ranger, works fine. Or get one of the old tank vent reservoirs and install that between the tank and aircleaner

 

[spade33]

just a thought i know you said you checked the connections ut did you check the one that connects the filler neck to the actuall tank? mine was rotted out pretty good and didnt leak but it smelt like crazy gas

 

[10secgoal]

AN lines have been known to smell also. Mine did once installed. But, I did do a cell at the same time without a vent, or check valve of any sort. I have other say they get the smell when they insatlled the AN lines. I guess the push lock stuff is supposed to smell less ?

 

[66forfun]

Ill look at the fill tube.
I don't understand how it could be a tank vent issue (cap it think), the problem wasn't there for the last couple of years when the mechanical pump was in there. I am running pro classic hose and russel fittings, I pulled the fuse and let it run out of gas hoping it was the carb and it helped but not much.

Thanks for the quick replys.

 

[jcode68]

AN lines have been known to smell also. Mine did once installed. But, I did do a cell at the same time without a vent, or check valve of any sort. I have other say they get the smell when they insatlled the AN lines. I guess the push lock stuff is supposed to smell less ?

Interesting, I have a strong gas smell as well, but no sign of leaks. Am using -6 AN Russel fittings & braided stainless lines. Will follow this thread with interest to see the root cause.

 

[dennis112]

Could the fuel pressure be overriding the carb floats? You might want to see if there is fuel dripping in the venturi of the carb after you have ran the car.

Sometimes sediment from the tank will cause the floats to stick open too.

 

[Iamdiffrnt]

I know a lot of the fuel cell manufacturers say that there will be a fuel odor after installing and that this is normal, I wonder if the an lines are made of the same material as the bladders in the fuel cells and are just porous enough for the same odor/effect. I do have to agree that even if this is "normal" and/or "Harmless" it would make me very uneasy about driving the car without knowing for certain.

 

[CraigMBA]

Call Russel and ask if that AN line has a vapor barier or not. I'm betting not.

I doubt the hose will leak, but you'll likely have to live with the smell if this is the case.

 

[66forfun]

I've narrowed it down to "its a stinky car"...lol. Got it narrowed down with my nose (I was starting to feel like a huffer).

I found 2 loose fittings at the filter (small contributer)

Seriously, it is not the tank vent (cap on the 66), I can put my nose right over the thing and not huff fumes, i think they are set up like a check valve???

its not the 8-an pro classic hose. same thing not stinky

It is a combo of the carb vents (lots of fumage out of the air cleaner) and the exhaust (big cam/overlap/running "black plug" rich right now).

So I was thinking of installing a fuel pump switch and running it out of gas before it gets garaged. Any harm in this approach? I would hate to have to mess with draining the bowls all the time.

 

[D.Hearne]

If your tank was full of "winter gas" that may be the source of the fumes. The Vapor pressure winter gas generates is higher than summer fuel. Nothing wrong with running the carb dry though.