Topic: Fuel smell

[jfrabat]

OK, so I have had this for a while, but since the Jeep is now my daily driver, it is driving me nuts.  After I drive for a while, there is a fuel smell near the gas cap (it actually comes from inside the body, where the hoses are; keep in mind I do not have that little plastic part on the bottom that hides the inside of the tub from the elements thrown that way by the tires).  I lowered the tank a couple of times to try to find the culprit, but no luck; I have replaced all the lines (except the ones that go behind the frame, which I have not been able to track down, but those are farther front and seem to be in good condition), and I have moved the tank (while out of the jeep) around to see if there is anything that leaks (and there is not).  I have also checked and replaced the cap thinking that was the problem, but no dice.

I SUSPECT that the problem is the two little rollover valves' seal give a bit when the tank presurizes, but I have seen nowhere that sells the rubber gromets they sit on.  Any other ideas where the smell could be coming from?

Felipe

[Jeffy]

Fule smell?  Petrol?  My first guess is the fuel line that connects the hard-line to the fuel filter.  It's under pressure and doesn't usually leak unless the system is charged.  Gas dries fast so you have to look for it after you've driven it.  If it leaks a lot you can feel gas behind the plate that covers the filter.

Keep in mind the tank isn't usually under pressure.  Pulling fuel does cause a vacuum though.  Though, many years ago there was a recall for the o-ring seal around the pump.  I still say the 2" L shaped hose though.

[jfrabat]

Fule smell?  Petrol?  My first guess is the fuel line that connects the hard-line to the fuel filter.  It's under pressure and doesn't usually leak unless the system is charged.  Gas dries fast so you have to look for it after you've driven it.  If it leaks a lot you can feel gas behind the plate that covers the filter.

Keep in mind the tank isn't usually under pressure.  Pulling fuel does cause a vacuum though.  Though, many years ago there was a recall for the o-ring seal around the pump.  I still say the 2" L shaped hose though.

Sorry for the typo...  Was supossed to be FUEL, as in gasoline.

I replaced the hoses from the fuel filler neck to the tank (twice, actually), so I am pretty sure it's not that.  Could be the filter, I have not checked that...  I don't know if it is pressure or vaccum, but after I drive the jeep for a while, and I open the gas cap, you can hear a rush of air (always though it was coming out, but I could be wrong).

[aw12345]

If somebody in your neck of the woods has an automotive style smoke machine have them take a go at it it should show where it leaks much better success rate then any other detection method

[jfrabat]

If somebody in your neck of the woods has an automotive style smoke machine have them take a go at it it should show where it leaks much better success rate then any other detection method

I Dont even know what that is...  much less if they have it!

[grumpygy]

The fuel Gauge Pump cover could be it.  It was a recall for that year.  Its a new Gasket and a thicker Plate with longer Screws.

[jfrabat]

The fuel Gauge Pump cover could be it.  It was a recall for that year.  Its a new Gasket and a thicker Plate with longer Screws.

I replaced that gasket like 4 or 5 years ago, though...

[grumpygy]

I replaced that gasket like 4 or 5 years ago, though...

It was the Plate that was needed cause the other warped to easy.

[sharpxmen]

you can put some pressure in it slowly and listen for hissing (i mean 1 or 2 psi, a hand pump is probably ok for that), you would probably want to use the return line and block the evap line, the main fuel line is fine since is holding a lot more than that at the regulator

[neale_rs]

The fact that the tank hold pressure of vacuum shows that it is fairly well sealed.  Mine does the same thing and I haven't figured out it is pressure or vacuum.  If it is pressure, then the vents might be blocked and the tank probably only smells when the pressure builds up a lot.  If it is vacuum, then why would it smell?  You would think the vapors would be pulled to the source of the vacuum.

[sharpxmen]

the fuel cap won't hold vacuum, will only hold pressure but to a certain limit (the fuel cap is built that way).

[neale_rs]

Thanks, that is a good thing to know.  On my YJ it only smells once in a while but it would be good to track it down.

[jfrabat]

It was the Plate that was needed cause the other warped to easy.

It would probaby be good to get a new fuel assembly then... Could even take the opportunity to finally switch the sending unit to the 20 gal tank that I now run!  I would still like to take the opportunity to replace all the tank's seals (including the rollover valves o r whatever those two little valves at the sides of the sending unit are).  Any idea on where to order all this stuff?  Like the cheapest reputable place to order the sending unit and gasket?

[grumpygy]

It would probaby be good to get a new fuel assembly then... Could even take the opportunity to finally switch the sending unit to the 20 gal tank that I now run!  I would still like to take the opportunity to replace all the tank's seals (including the rollover valves o r whatever those two little valves at the sides of the sending unit are).  Any idea on where to order all this stuff?  Like the cheapest reputable place to order the sending unit and gasket?

No but if you find it post it.

[jfrabat]

No but if you find it post it.

I found the fuel sending unit, fuel sender unit gasket, the fuel vapor valve, and the fuel check valve seal in www.4wd.com.  I think I may just order the whole thing there and call it good!  I will also change the filter just in case this is the cause, but I can get that in Panama.

You can see the schematics and the parts themselves here.