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Posted by: billh1963 Apr 18 2014, 11:55 AM

When driving the car (engine is a 2.2L 6 with triple Webers) I frequently smell gas. This is with the targa on or off. The smell comes and goes...it's not consistent; however, it always occurs

If I stop the car and check around the car (with the engine running) I don't smell it. With the engine running I have checked everywhere and don't see or smell anything. No drips or puddles under the car, around the carbs, etc. I have checked connections on the fuel pump and nothing there.

I have thought of two possibilities:
1. Leaking fuel line in the tunnel (which I should smell all the time...right?)
2. Fumes coming into the cockpit from the engine compartment.

Any other thoughts?

Update: 5/3
Drove the car extensively today and, as usual, the gas smell comes and goes. Stopped while the smell was strong and checked around the carbs...dry
Looked under the car...dry
Opened the trunk...no smell.
Even pulled the gear shift to see if there was a gas smell in the tunnel...nothing

The only thing I see is this line is hanging out in space...could the smell be coming from here?
Should I cap it or does it need to connect somewhere?
Remember...this car has triple webers...it's not fuel injected.

Posted by: veekry9 Apr 18 2014, 12:07 PM

When driving the car (engine is a 2.2L 6 with triple Webers) I frequently smell gas. This is with the targa on or off.

Uh-oh.
1)Carry an extinguisher.
2)Check the floats/seats.
3)replace all aged lines.
4)Park outdoors.
5)Keep away from open flames/sources of ignition.
6)Keep a weather vane.(Lightning?).

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Posted by: Spoke Apr 18 2014, 12:09 PM

I had a come-and-go fuel odor in the car. Traced it to an oozing fuel line connection under the fuel tank. Never leaked to a puddle, couldn't smell it when investigating under the front hood.

The area wasn't wet but showed signs of seepage. It only takes one small drop of fuel to really smell up the interior.

You may want to lift the tank out to investigate.

Posted by: billh1963 Apr 18 2014, 12:13 PM

QUOTE(veekry9 @ Apr 18 2014, 02:07 PM)

When driving the car (engine is a 2.2L 6 with triple Webers) I frequently smell gas. This is with the targa on or off.

Uh-oh.
1)Carry an extinguisher.
2)Check the floats/seats.
3)replace all aged lines.
4)Park outdoors.
5)Keep away from open flames/sources of ignition.
6)Keep a weather vane.(Lightning?).

I do carry a fire extinguisher and the carbs are freshly rebuilt from a well known builder. The smell isn't that strong (like gas pouring out)...however it is there when driving.

There is NO gas smell when parked.

Posted by: billh1963 Apr 18 2014, 12:15 PM

QUOTE(Spoke @ Apr 18 2014, 02:09 PM)

I had a come-and-go fuel odor in the car. Traced it to an oozing fuel line connection under the fuel tank. Never leaked to a puddle, couldn't smell it when investigating under the front hood.

The area wasn't wet but showed signs of seepage. It only takes one small drop of fuel to really smell up the interior.

You may want to lift the tank out to investigate.

That's on my list if all else fails. It's over half full so really don't want to drain the tank if I can help it.

Posted by: bulitt Apr 18 2014, 12:18 PM

Do you still have the charcoal canister and expansion tank on top of the fuel tank?
Is the vent tube connected from the fuel tank to the charcoal canister. If you don't
have all of this stuff working you may be getting fumes venting from the gas tank.

Easy fix if the canister/expansion tank have been removed or are not functional. Make a small hole in the large overflow tube coming out of the tank filler neck.
Feed the small vent tube down into the hole in the overflow tube about 6". Make the hole small enough so it is tight around the vent tube.
Andy's idea and I guess works well for him.

Posted by: toolguy Apr 18 2014, 12:18 PM

I would not drive the car until you KNOW 100% that all the fuel lines are good. . If you still have the plastic line thru the tunnel, replace it and all the flex hoses. . then look for the carbs to be leaking. . main jets or float bowl drains. . feel the bottom of the float bowls with a tissue paper while running and see if there is any liquid gas. . .
Do you smell it in the front trunk ??
Another possibility it the gasket around the top of the gas tank filler neck with the little bolts. . that is especially noticeable with full tank going around corners. . also the tank overflow drain hose should protrude out of the tank area floor and below the steering belly pan. .

Posted by: Qarl Apr 18 2014, 02:14 PM

What type of fuel lines do you have? Gas with ethanol can corrode the regular fuel lines unless they are lined with PTFE.

Gas vapors can also permeate through the lesser quality or older rubber fuel lines.

And as others have said.

1. Gas cap seal
2. Evaporator cannister system (if in place).
3. Small leak in fuel line fitting.

Posted by: john77 Apr 18 2014, 04:08 PM

I have exactly the same problem with my 6 conversion. It started 2 weeks ago mid way through an auto cross event. I'm dropping it in the shop next week (I'm not driving it until then), so if you've not figured it out by then I'll post back with what they find.

Posted by: billh1963 Apr 18 2014, 04:40 PM

QUOTE(john77 @ Apr 18 2014, 06:08 PM)

I have exactly the same problem with my 6 conversion. It started 2 weeks ago mid way through an auto cross event. I'm dropping it in the shop next week (I'm not driving it until then), so if you've not figured it out by then I'll post back with what they find.

That's interesting....

Everyone has some good suggestions that I need to check out.

I'll be checking various components tomorrow and report back

Posted by: 76-914 Apr 18 2014, 05:01 PM

I'm with Zach on this one.

Posted by: billh1963 May 3 2014, 03:41 PM

Update...see first post

Posted by: wobbletop May 3 2014, 04:02 PM

As toolguy mentioned, check the tank overflow line. For some reason mine was not routed down and out of the car. When I did hard left hand corners with a full tank, gas would come out and end up in the passenger compartment through holes in the bulkhead.

Posted by: billh1963 May 3 2014, 06:37 PM

QUOTE(wobbletop @ May 3 2014, 06:02 PM)

As toolguy mentioned, check the tank overflow line. For some reason mine was not routed down and out of the car. When I did hard left hand corners with a full tank, gas would come out and end up in the passenger compartment through holes in the bulkhead.

I haven't pulled the tank; however, the overflow is connected at the top and I can see the hose under the car. I have about a 1/2 tank of fuel now and was driving local streets to detect the smell....no hard corners

Posted by: JStroud May 3 2014, 11:02 PM

The "line hanging in space" would have gas fumes coming from it, probably should route it down like the overflow hose, don't cap it.

Jeff

Posted by: Cap'n Krusty May 3 2014, 11:16 PM

It's not like I really read all the somewhat clueless replies, but I can't believe no one told you to FIX the open vent line. It is OBVIOUS that some posters didn't even completely read the original post! It's got a freakin' PICTURE, for Pete's sake! That stray line runs from the evap can to the engine. There are two, one to a nipple on the fan shroud, and one to the air cleaner. They MUST be connected, and connected correctly. That's your gas smell! This, BTW, has been discussed numerous times right here in the Garage forum, and the answer to the problem has nearly always been the same. It's a PASSIVE emissions system, and it makes absolutely NO sense to disable or eliminate the plumbing!

The Cap'n

Posted by: mepstein May 4 2014, 08:02 AM

so im guessing with the car running, more air is pushed into the system (engine fan) and more fuel vapor escapes. Hook up the line and the fuel vapor goes to the right place. Looks like a very simple fix.

Posted by: billh1963 May 4 2014, 09:32 AM

QUOTE(Cap'n Krusty @ May 4 2014, 01:16 AM)

It's not like I really read all the somewhat clueless replies, but I can't believe no one told you to FIX the open vent line. It is OBVIOUS that some posters didn't even completely read the original post! It's got a freakin' PICTURE, for Pete's sake! That stray line runs from the evap can to the engine. There are two, one to a nipple on the fan shroud, and one to the air cleaner. They MUST be connected, and connected correctly. That's your gas smell! This, BTW, has been discussed numerous times right here in the Garage forum, and the answer to the problem has nearly always been the same. It's a PASSIVE emissions system, and it makes absolutely NO sense to disable or eliminate the plumbing!

The Cap'n

This has a 6 and I see no line returning to the engine. Can it be capped or will that build pressure?

Posted by: McMark May 4 2014, 09:52 AM

Do not cap the lines from the tank. If you seal it tight enough, your fuel pump will keep sucking fuel, but no air will enter the tank to fill the void. After awhile you start generating vacuum in the tank and the car will stall out as the vacuum increases and the pump can no longer suck hard enough.

You can run a longer line down under the car, but you may still get a fuel smell.

Two other thoughts on where the smell may come from:

1. Fuel filler leak - while cornering with a full(ish) tank the fuel may seep out and leaking seals and this fuel will evaporate and you will smell it. The canister around the filler neck also gathers some fuel slosh on a full tank. If the small line between the tank and the canister is old and cracked it can allow some fuel to leak out.
2. Carb Mixture - if the car is running rich (especially on overrun, which all carbs do) you may smell a rich exhaust mixture as the fume flow over the car when you pull up to a stop. My car does this when it's cold and the warmup enrichment in running. The exhaust fumes are sort of chasing you down the road, and when you stop, they keep moving forward and you can smell them.

Posted by: JStroud May 4 2014, 10:00 AM

Bill, unless they removed them you should have two plastic lines running from the front trunk near the brake fluid reservoir going down thru the fender well under the driver rocker panel into the rear fender well then into the engine compartment below the oil tank. On your charcoal filter the line coming out on the side with the small tube should be hooked up to one of the plastic lines then hooked to the air outlet port on your fan housing. The other end "hanging in space" should be connected to the other plastic line the connected to the air filter housing. This would put the system back functioning.

If you don't have the plastic lines you can route the hanging line down and under the car like the overflow tube like I stated earlier but don't cap it.

Also if that charcoal filter line is disconnected, where does the one on the other side go, they both would have fumes coming out.

Hope this helps,
Jeff

Posted by: larryM May 4 2014, 09:01 PM

X2 on Jeff's comments - but you never told us if you are running a return line & old style 3-pipe pump -

if you have return fuel circulating it makes a LOT of vapor - cut off & plug the return line (at the tank) if you have one - it is totally useless on a carburetted car

- throw away or sell the oem pump & install a Facet - $40

be sure you have an open vent at the filler neck so the atmospheric psi can get back into the tank as you "suck" out fuel (that tiny pipe) - vent it overboard outside the trunk

throw away that canister

buy a new gas cap with decent seals - abt $35 from a 356 supplier

if still a problem, run a vacuum line from the big neck pipe to the intake manifold & suck out the fumes (that was the whole purpose of your canister & its lines) - your oem 4 had a suction line thru the body for that - hope you did not cut it off

.

Posted by: GeorgeRud May 5 2014, 08:06 AM

On my conversion, I attached one vent line to the nipple on the engine shroud, and the other line leading to a fitting I installed on my rain hat air filter. This helped with the fumes by actually pushing and pulling air through the carbon canister. It was pretty bad before I got around to connecting the lines.

Posted by: Cap'n Krusty May 5 2014, 08:18 AM

QUOTE(GeorgeRud @ May 5 2014, 07:06 AM)