Fuel smell - Air Vents

[madstudios]

Hi everyone!
Today I drove about 2 hours in a hot summer day. When I was driving back home, I started to smell gas, apparently coming from the air vents.
There is no visible sign of fuel leak.
Any thoughts?


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

[Michael]

Open up the fuel pump area, remove the boot and check for any leaks there. Start the engine and let it idle and check again. If you see nothing look under the car and make sure your accumulator lines are not leaking (again while idling). If you see no leaks then replace your fuel cap.

[Jonathan]

Could also be the seal on the fuel sender. If it isn't perfectly seated/sealed, it can come sloshing up around the edges when you're driving and then the air rushing by takes it from there into the cabin.

A good test to see if this is happening is to gain access to the top of the fuel tank by removing everything from your trunk, including the carpet board and spare tire, and then remove the access cover that's under the spare tire. You can now see the top of the tank and fuel sender. Check to see if there is any obvious fuel wet spots first. If not, and there may not be if it has evaporated, leave everything out of the trunk just like you have it and go for a little drive around the block. While going about 10 mph or so, slam the brakes on hard and come to a complete stop (make sure your neighbour isn't driving right behind you first!). Now pull over safely and have a look at the top of the tank and fuel sender and see if it is wet. If it is, you know where your leak is. Credit to Dave S. (of course) for sharing that little trick with me a year or so ago.

[David T]

Was the tank full or near full at the time? Typically a fuel smell is going to be something to do with the fuel tank. A bad fuel cap, a deteriorated fuel boot and cover, a leak from the sending unit, a hose, something. A wet spot is a great visual indicator but you aren't always going to see one. A through visual inspection of the fuel tank is the first step. To do that you must remove the access panel under the spare tire.

[dmcnc]

After two hours in a hot summer day, you probably have plenty of gas vapors built up in the tank as the radiator fans will heat up your gas tank. Lots of places around the tank where those fumes could be pushing through. If this happens again pull your gas lock and see if fumes pressure out. If they do, see about insulating your tank from the radiator fans. Hervey's hot-air dam is a good reference.

http://www.deloreanautoparts.com/delorean-parts/images/delorean-hot-air-dam-place.jpg

That said I'd still check for leaks around the fuel tank as recommended by everyone else ^

[madstudios]

Thank you everyone for so many tips, you guys are awesome! ;)
I'll check everything tomorrow.
Today it was about 95 degrees here in Sao Paulo, I went to a car show in a small town 50 miles from here. Everything went well on the way there (no smell at all), but I parked the car in the sun about 3 hours, and on the way back I've noticed the smell inside the car. This was the hottest day ever that I've used the car in a highway. I usually drive in the city.


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772https://uploads.tapatalk-cdn.com/20170213/8654d548a6074692340f82d2ed47ba90.jpg

[FABombjoy]

Tank vapors should not build up, but should vent into the charcoal canister. You may want to check the vapor lines at rollover valve / fuel fill area. These are what mine looked like last year.

48921

That's the hose going from the rollover valve to the hard vapor line on the frame. There is also a short hose that connects the fuel filler neck to the rollover valve. IIRC early versions of this hose are known to go bad.

You have to pull the inspection plate just below the fuel fill to inspect these.

[David T]

Tank vapors should not build up, but should vent into the charcoal canister. You may want to check the vapor lines at rollover valve / fuel fill area. These are what mine looked like last year.

48921

That's the hose going from the rollover valve to the hard vapor line on the frame. There is also a short hose that connects the fuel filler neck to the rollover valve. IIRC early versions of this hose are known to go bad.

You have to pull the inspection plate just below the fuel fill to inspect these.

While you are correct that you should not get any vapors, if there are any leaks in the tank area you will get fumes. Find and fix any leaks and if you still get fumes there *could* be a problem with the vapor system. On some cars I have found the hose coming off the bottom of the vapor canister all plugged up with insect stuff. You can see that hose coming out of the bottom of the left, rear pontoon. On my car I had a problem with the gas cap. It was not sealing well. The rubber gasket was swollen and the spring was not able to seat it properly. Took it apart, cleaned it all up and now it's fine.

[Drive Stainless]

A failed rollover valve will also cause pressure to build in the tank until you have liquid gasoline & vapors escaping through the gas cap.

[dmcnc]

A failed rollover valve will also cause pressure to build in the tank until you have liquid gasoline & vapors escaping through the gas cap.


Very true, and the smaller hose off the rollover valve tends to kink with age. The article below has a good rundown on fuel smell sources.
http://support.delorean.com/kb/a42/fuel-smells.aspx

[madstudios]

Could also be the seal on the fuel sender. If it isn't perfectly seated/sealed, it can come sloshing up around the edges when you're driving and then the air rushing by takes it from there into the cabin.

A good test to see if this is happening is to gain access to the top of the fuel tank by removing everything from your trunk, including the carpet board and spare tire, and then remove the access cover that's under the spare tire. You can now see the top of the tank and fuel sender. Check to see if there is any obvious fuel wet spots first. If not, and there may not be if it has evaporated, leave everything out of the trunk just like you have it and go for a little drive around the block. While going about 10 mph or so, slam the brakes on hard and come to a complete stop (make sure your neighbour isn't driving right behind you first!). Now pull over safely and have a look at the top of the tank and fuel sender and see if it is wet. If it is, you know where your leak is. Credit to Dave S. (of course) for sharing that little trick with me a year or so ago.

I did the test, and the fuel sender was not properly seated.
https://uploads.tapatalk-cdn.com/20170222/07e1f7aa45d31bc2f56506b616bc62a4.jpg
I also made myself a hot air dam!
https://uploads.tapatalk-cdn.com/20170222/d1c07bb71265ca6c7f29b18aa03e78de.jpg
I'll take the road next weekend and see how it goes.
Thanks!


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772

[dmcnc]

Nice! Let us know how it goes!

[Will F.]

I just had a very similar issue. Mine turned out to be broken fuel lines. The inner tube cracked and was just held on with the dust cover. lol Thank goodness Im in driving distance from Pj Grady.


Will

[Jonathan]

Picking a thread with "fuel smell" in the title...

Is there anything that comes to mind as to why one might smell fuel more so when the tank is closer to empty than to full? I'm still not 100% convinced I am smelling fuel, but over the past couple of weeks, it seems like there is a smell of fuel in the cabin. Not always and not terribly consistent. Seems like it is more noticeable when making a full turn at an intersection (so either the braking part or the momentum shift of the car from side to side). And perhaps more noticeable when the tank has less in it than soon after a fill-up.

I've checked recently (visually) the top of the tank, sender seal, under the fuel pump boot and flexible hoses from the tank to the hardlines. No obvious signs of fuel or other wet spots.

Just curious if anyone has an "ah-ha" idea that would lead to the smells being more evident when the tank isn't full.

[kings1527]

Picking a thread with "fuel smell" in the title...

Is there anything that comes to mind as to why one might smell fuel more so when the tank is closer to empty than to full? I'm still not 100% convinced I am smelling fuel, but over the past couple of weeks, it seems like there is a smell of fuel in the cabin. Not always and not terribly consistent. Seems like it is more noticeable when making a full turn at an intersection (so either the braking part or the momentum shift of the car from side to side). And perhaps more noticeable when the tank has less in it than soon after a fill-up.

I've checked recently (visually) the top of the tank, sender seal, under the fuel pump boot and flexible hoses from the tank to the hardlines. No obvious signs of fuel or other wet spots.

Just curious if anyone has an "ah-ha" idea that would lead to the smells being more evident when the tank isn't full.

I get more of a fuel smell when it's hot out and my tank is 1/2 or less. Maybe closer to 1/4. I've checked EVERYTHING...all that was mentioned previously. The one thing I'm considering are my vacuum lines that are Hervey's silicone replacements. I'm wondering if the diameter is smaller than originally designed and not able to take the vapors back to the canister "fast" enough. Have to try that someday.

[Lwanmtr]

I just cleaned out my tank and found that the smell actually got stronger after I pumped all the gas out..no idea why.
In fact, even after cleaning it there still seems to be fuel vapors...though that could be because I have my lines still not connected.

I was smelling fuel before and when I pulled the pump I found that the connector on the pump itself was loose, as well as no clamp securing the pump in the boot...so those are areas that might be good to check as well if it comes up again.

[madstudios]

I get more of a fuel smell when it's hot out and my tank is 1/2 or less. Maybe closer to 1/4. I've checked EVERYTHING...all that was mentioned previously. The one thing I'm considering are my vacuum lines that are Hervey's silicone replacements. I'm wondering if the diameter is smaller than originally designed and not able to take the vapors back to the canister "fast" enough. Have to try that someday.

Yes, I had fuel smell when it was hot too, so I've made myself a hot air dam, just like hervey sells, to keep the tank cooler. I had no more fuel smells so far.


Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772