1979 Lincoln Continental - Fuel Odor When It's Not Running

[SomeoneWeird]

Hi all,

I recently bought a 79 Continental. It's in great condition visually, but it has one big nagging issue I can't quite figure out. When I park the car in the garage, over the course of a few hours, the garage starts to smell more and more like a gas station - a strong fuel smell. If it's been in there for a day plus with the garage door closed, the odor even starts to seep into the rooms of my house above/adjacent to the garage. (For what it's worth, I don't notice any odor in the interior of the car when I'm driving.)

I've replaced the gasket on the fuel tank (which was leaking a little), replaced the EVAP hose, and also replaced the fuel pump. The car passed smog, but the odor isn't any better. For what it's worth, when I try to sniff out where the fuel smell is coming from, I smell it most strongly from the engine bay. Specifically, the part of the engine bay in front of the driver's seat - between the driver's wheel well and the engine. Roughly where I've circled in the attached picture.

I haven't noticed any leaks below the car.

Any thoughts as to what it might be that's causing this?

Thanks for any help!

[Dan Szwarc]

The fuel pump is on that side of the 400 motor, visible from under the car. There should be a flex line from the car body to the pump and a hard line up to the carb from there. My guess is the flex line is rotted or leaking from either clamp.

Jack it up, crawl under, and push on the rubber line a little and look for saturation leaks. I saw one line that was so bad, the slightest movement caused leaks and it seeped ever so slowly. It’s only 12-14” line and easy to replace, but only do it is the tank is half empty or lower. 3/8” fuel rated line wins what you need. By at least 18” and cut to length. Use fresh stainless worm clamps.

It’s in your pic. The flex is highlighted in yellow and the hard line is blue.

[1Bad55Chevy]

Is the 79 like the other Marks with a rollover valve on the top which hooks the EVAP line? If so you could have a leak there or somewhere else along the EVAP line. If Dan's advice dosen't work you will need to do a smoke test on the EVAP system to find the leak. It will be cheaper to get a shop to do this for you then buying a smoke machine.

If you do end up buying a smoke machine you would use a fuel cap adapter and pressure test the system with the rubber hose connected charcoal canister disconected and blocked. If no leaks are found hook the smoke machine to the rubber hose connected to the charcoal canister and with the fuel cap installed and re test to ensure the fuel cap is sealing. This is how I test the EVAP systems on modern cars and it works well but they have a few more pieces that have to be checked.

[1Bad55Chevy]

The fuel pump is on that side of the 400 motor, visible from under the car. There should be a flex line from the car Boyd’s to the pump and a hard line up to the carb from there. My guess is the flex line is rotted or leaking from either clamp.

Jack it up, crawl under, and push on the rubber line a little and look for saturation leaks. I saw one line that was so bad, the slightest movement caused leaks and it seeped ever so slowly. It’s only 12-14” line and easy to replace, but only do it is the tank is half empty or lower. 3/8” fuel rated line wins what you need. By at least 18” and cut to length. Use fresh stainless worm clamps.

It’s in your pic. The flex is highlighted in yellow and the hard line is blue.

I just noticed the line you highlighted... looks like it's just about to fall off! You know that thing has to be leaking.

I personally hate worm clamps! They look absolutely terrible under the hood of a car. When I see a car with worm clamps I instantly think DIY. I suggest using spring clamps or fuel injection hose clamps since they actually look OEM.

[John Mc]

The fuel pump is on that side of the 400 motor, visible from under the car. There should be a flex line from the car Boyd’s to the pump and a hard line up to the carb from there. My guess is the flex line is rotted or leaking from either clamp.

Jack it up, crawl under, and push on the rubber line a little and look for saturation leaks. I saw one line that was so bad, the slightest movement caused leaks and it seeped ever so slowly. It’s only 12-14” line and easy to replace, but only do it is the tank is half empty or lower. 3/8” fuel rated line wins what you need. By at least 18” and cut to length. Use fresh stainless worm clamps.

It’s in your pic. The flex is highlighted in yellow and the hard line is blue.

I just noticed the line you highlighted... looks like it's just about to fall off! You know that thing has to be leaking.

I personally hate worm clamps! They look absolutely terrible under the hood of a car. When I see a car with worm clamps I instantly think DIY. I suggest using spring clamps or fuel injection hose clamps since they actually look OEM.

Could not agree more on the hose worm clamps, they scream amateur. I put them down with yellow or red spark plug wires.

[TonyC]

Well...I have to be the dissenting voice on worm clamps. I see them as far superior to the Jesus-clamps originally used. That said, that superiority is of course contingent on the source manufacturer(s) of the clamps. I've learned that the clamps you'll find in car-part stores are indeed deserving of all the vitriol posted above me; they will strip out well before one reaches the level of tightness one needs. On the other hand, worm clamps you'll find in a hardware store are made differently, by different manufacturers, with far superior construction standards. You'll find all the sizes you'd need, but with quality that matches, or I dare say surpasses, the factory Jesus-clamps.

---Tony

[Dan Szwarc]

The industry uses constant tension clamps for a reason. They’re easy to install and they don’t leak. They are not made to be reused by the consumer. They are intended to be removed and replaced using the proper tools. With proper hoses, proper installation locations, and new parts, they work great

Most of us don’t have that luxury on our 45 year-old plus cars, without hoists, with rotted or hardened hoses, crappy aftermarket hoses, etc. Proper stainless steel worm clamps work fine on properly sized hoses and clean connections.

[1Bad55Chevy]

Don't matter how you twist it that looks absolutely terrible.

I work on late model cars everyday and I don't own a special tool to remove spring clamps, I use channel locks or slip joint pliers. I know they make special pliers that lock but I don't have them and I have never had an issue. A fuel injection clamp or a spring clamp looks exponentially better then a worm clamp. If you have a high end custom the heat shrink hose clamps looks the absolute best IMO.

[Dan Szwarc]

I trim my clamps to length and position them, but show us how you clamp with alternates.

Some clamps are supposed to be tower clamps, which are lower quality than original used to be and not stainless or plated steel anymore.

Any more clamp discussion, and I’ll split this topic.

Did OP did his fuel smell issue?