AlfaMetal

Hello All,
New member, so please bear with me.
I have scoured the forums for an answer to this issue and haven't come up with a solution:

I bought a 2000 LS400 for $500 from a relative. Car has 200k on the clock but is in really nice shape considering.
He mentioned that about a month before the sale, he had spilled some gas in the trunk and that you could faintly smell it in the cabin. I figured no big deal. I removed all the carpet and trim pieces from the trunk, scrubbed them down and left them in the sun. They smell fine now. Next, i scrubbed the sheet metal with water/vinegar mix, dried it, and left the trunk open for a couple days. The smell persisted. Left a bag of charcoal in the trunk....still smelled.
So next I figure, by some crazy coincidence, there is an actual fuel leak that has cropped up at the same time the spill happened. I took the car to a shop and had them do a smoke test:
No leaks and the evap system holds pressure.
​​​​​​I do not see any physical pooling of gas anywhere in the trunk either.
The shop did a scan and no codes were present. So I'm assuming the purge valve on the charcoal canister is functional.
I checked the overflow tube and it is indeed still routed through the floor of the trunk.
The smell dissipates when the trunk is opened for awhile but reappears overnight, without the car being run/refueled.

So my questions are:
1: Is it somehow possible that the spilled gas from two months ago is still causing an odor even after all my cleaning efforts? (Trim and carpet have not been reinstalled)
2: What would be my next diagnostic step, assuming the scenario in question #1 is not the case? Fuel dye leak check?

I know this subject has been beat to death but I feel that I've covered a lot of bases here and still have no resolution.
I'd hate to get rid of the car but it makes it almost unusable.

Thanks in advance for any help.

timmy0tool

iTrader: (7)

check around the rubber gaskets of the filler neck, and the vent tube at the top of the tank.
gas leaks are tough to find since gas evaporates quickly and the leak is undetected.

AlfaMetal

Hi Timmy,
Thanks for the reply. I looked at these spots and did not see anything obvious. Would the smoke test not have shown leaks from these areas?

YODAONE

Replace all fuel tank to fittings rubber gaskets - fller neck, emmission fittings and fuel pump access hole. mind the torque.

Also replace fuel tube overflow and clamps (OEM)

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/880409-gas-fill-up-overflow-drain-tube.html

AlfaMetal

Thanks for the reply. Do you have a recommendation for a vendor for these items? The couple places i found showed discontinued.

AlfaMetal

Also, should I remove the fuel tank entirely to replace these gaskets?

YODAONE

Gas tank exploded parts diagram for 2000 LS400.


Tank removal not necessary. Rear seat removal is (77169A) Rubber gasket #s: 77169A, 77179A, 77177 77178 Leaking possible from a myriad of other hoses.

AlfaMetal

thank you very much