Sorting out my new toy - fuel smell

[Bucketlist]

I put 10 gallons of fuel in my 1981 sc today for the first time. I have a serious fuel smell from the gas tank area into the passenger compartment. I don't see any leakage at the top or bottom of the tank. Are there any common solutions to this or do I just start replacing all of these 30 year old rubber hoses?
While I was looking I found this front compartment that I didn't know was there and wondered what was its purpose and what was once plugged into these loose wires(plugs)?

[porsche moose]

A/c

[Bob Kontak]

That's called the smugglers box. Usually holds the AC evaporator. In the way back, there could have been a Webasto heater in there.

Gas cap is most common issue for smell. Check lines from trunk to driver's side inner fender to the expansion tank (vapor recovery). Make sure the system is sealed in the front - i.e., no open ports.

[5String43]

That hole is called the smuggler's box. If memory serves, it originally, in the early cars, was where a gas-powered heater was situated. In later cars like SCs, I seem to remember that part of the A/C system lived in there.

As for the gas smell, sometimes the gasket between the fuel gauge's sending unit and the tank can leak. If it does so, even a little, you'll smell gas.

[Ayles]

I was able to block off the one pipe with a rubber cap from a plumbing supply store.

I have an SC as well, interesting to see the differences in the smugglers box.

[ossiblue]

Fuel smell--check all hoses for the evaporation system as well as the sending unit gasket and gas cap gasket. The fuel evaporation hoses not only route from the top of the tank, but also from the neck of the filler pipe. Trace the path of all hoses that connect to the tank. Evap hoses will not always show signs of moisture so check carefully. Also, check all places the evap hoses terminate as cracks in the evaporation tanks can produce the smell as well. Finally, be sure the overflow from the filler pipe is connected to a hose and that hose connects to a residual tank by the front headlight. Sometime the tank is missing and the hose dumps into the atmosphere.

[G50911]

i had the same issue and it was the gasket for the fuel sending unit. a tiny amount lf gas leaked and i smelled it bigtime. its fixed now

[Bucketlist]

I forgot to mention this is a Row car if it makes a difference. I have traced all of these hoses and I think my best bet is to replace some them. The one that goes up behind the fuse box and through the inner fender looks suspicious but then it is capped off in the fender well.

[Scooter]

Check your hoses to the expansion chamber in the front trunk, to the evaporator chamber in the front driver's side fender and the charcoal canister in the passenger rear fender. Also, check the chambers for cracks. Here is a schematic of the emissions:

[moneymanager]

Before you do a lot of work add a second gasket to the cap, or cut a piece of inner tube rubber to fit under the existing gasket. Takes five minutes, costs nothing, has worked twice for me.

[steely]

I'd still go with inspecting and replacing the fuel lines, or at least start planning to and carry an extinguisher.
With the A/C evaporator missing, the odor could be coming from the unblocked vent, and the fuel pump and return line to the tank are just inches away from the steering rack (the top of which is visible in the smugglers box). Crawl under there and see what it looks like. Yes, the fuel evaporator could be suspect too, but the risk factor is much lower.

[hydrocrust]

Check hoses to/from fuel expansion chamber. That's what it was on my 82SC. And the chamber had a hairline crack, too. New chamber and hoses (high Temp/fuel grade stock from McMaster) and no more smell.

[RSBob]

tighten all the clamps on the fuel lines, since they loose tightness as the hoses shrink - its cheap and easy

[Smoove1010]

I had this problem in my '87 - it turned out to be the 4" piece of line connecting the tank to the fuel pump. The fabric cover was moist to the touch with gas. Once removed, I split it open to see how badly deteriorated it was - this was a sobering sight:
Fuel smell in cabin

BTW - that's a really good fuel-smell-in-cabin thread that you'll want to review.

Good luck!
GK

[Bob Kontak]

Originally Posted by Hot Euro

The one that goes up behind the fuse box and through the inner fender looks suspicious but then it is capped off in the fender well.

Capped off vapor recovery system will add to your problem.

If it is an effective seal where capped off the tank will build pressure and vapors will find a way to leave if any other gasket/seal is marginal. Try uncapping it and see if the smell location changes. Specifically, will the smell come out of the hose?

If so you need to get that system working. I don't know for certain if ROW cars have vapor recovery, but yours would be gray market so would have had the system to get into the US. I think ROW had vapor dump to atmosphere but not sure. You sure don't want vapor dump to inside the front trunk.

[Bob Kontak]

Another thought before uncapping the evap hose on the wheel side of the inner fender.

Change the gas cap (or do the inner tube trick mentioned by moneymanager). $10 or so as this is common to leak. Park your car with the trunk lid up and have the sun on your gas tank. It will heat it up and vapors will increase. Try ten minutes and loosen the gas cap and listen for pressure escaping.


If no escaping pressure, spray soapy water on the top of the tank (sending unit seal) and on all the vapor hoses to see if vapors are escaping. This will not help with fuel lines

Spray the snot out of that little expansion chamber.

[RWebb]

FIRST, disconnect the battery so the car and garage do not blow up or burn up!

I would replace all the rubber fuel hoses with new ones, using ethanol rated hose. Some models have a specific failure point which IIRC is metal hose.

Next, check all the emissions hoses and tanks. Check the tanks for leaks via the pressure test noted above.

Squeeze the vapor recovery system hoses and see if they are pliable. See if they are dark yellow or brown. See if they have ANY hairline cracks. If they fail any of these 3 tests then replace them all. Use a hose that is rated for fuel vapor. Do NOT use regular PVC tubing from a hardware store.

Check all clamps and be certain some idiot did NOT put clamps on that will bite into the hose. Replace them with safe clamps.

Check the seal/gasket for the fuel tank sensor as per above.

After that, you will want to replace all the rubber BRAKE hoses with new rubber; flush the old fluid out; add new quality brake fluid and bleed the system.

Then replace all other old fluids or fluids of an unknown age.

[Bucketlist]

I tightened all of the hose clamps (most were loose). Tightened the fuel sender nuts, also loose. When I loosened the gas cap to check the gasket it relieved pressure so I think that may be OK. I think the smell has decreased. I was also working with a defective fuel accumulator and replaced it and the fuel filter so it may take a few more days to know for sure if my odor is gone.

[Bob Kontak]

Originally Posted by Hot Euro

I tightened all of the hose clamps (most were loose). Tightened the fuel sender nuts, also loose. When I loosened the gas cap to check the gasket it relieved pressure so I think that may be OK. I think the smell has decreased. I was also working with a defective fuel accumulator and replaced it and the fuel filter so it may take a few more days to know for sure if my odor is gone.

I am pretty sure that your vapor recovery system is blocked allowing pressure to build. I do not know the downside of this but it is not right.

In the post above, I wanted you to keep the hose blocked so it can build pressure. And it does. Good for testing, not so good for dealing with vapors. Texas will soon put your under trunk lid temp way up there if left standing in the sun and the pressure will build lots. If you tighten up all the pressure release points (clamps, etc) but keep the vapor recovery system plugged something may give and surely the worst scenario is you die - but, on the upside, it will be a painful, screaming, fiery death.

Unplug the hose in the inner fender. At least the pressure will vent outside vs in the trunk until it's rectified.

[Bucketlist]

I will unplug the hose in the inner fender right now then work on the rest of the problem.
Thanks for the warning!
Do you have any idea where this should go?

This is the origin of the hose:



Hose capped:




Hose uncapped: