PNWdriver

First of all, hello to everyone.

My mother’s car is a 1990 Legend LS sedan, which has been in the family since ~ 1994. I am not so familiar with Acura/Honda as I have driven & worked on primarily VW/Audi products. I hope you can help me out.

Problem: Last week it began to have a strong gas odor seeming to stem from the left (driver) rear backseat (and to a lesser extent, the left front trunk area). It was noticeable after having been parked in warm weather for a day, after having an attendant fill the tank that morning, which was overfilled since there is a gas ‘trail’ down the side below the filler door.

She said that after being parked all day, there was a puddle of gas on the pavement beneath the filler area. There is no odor when outside the car, but it hits you strongly as soon as you open the door after the car has sat for a while – the same when the car has been parked overnight.

There is no gas puddle now, but after 5 days, the odor is still strong inside.

NOTE: there is no fuel odor anywhere under the hood or underneath the cabin, so I’m ruling out any injector seals, broken hoses, fittings & hardlines, etc. in those areas.

What I’ve done so far:
- Put the rear on stands & inspected under the filler/tank area & lines running to the engine bay.
- Put the front on stands & inspected under firewall area & engine bay.
- Checked the areas around the fuel filter, carbon canister, FPR, hoses, hard lines, fittings, etc. – no seepage or odor.
- Removed floor & left side trunk panels – found nothing except the smell in the general area; sniffed every hole in the body structure – no localized smell.
- Removed fuel pump cover – nothing but undisturbed dust.
- Removed gas cap & blew through the vent hole which seems unobstructed (so I’m assuming it’s OK).
- Flushed water through the overfill hole at the gas cap.
- Removed rear seat cushion (lower).
- Removed left rear wheel & inspected the filler hose to the tank, fittings, surfaces using a mirror.

To my nose, the odor seems concentrated in the left rear cabin/left front trunk, but no evidence of gas having run on any surface. I’m attempting to remove the rear back cushion, but can’t seem to budge the upper hooks.

I have read over both the Haynes & Chilton manuals, and all fuel system components seem to be operating normally. I’ve searched your forum but nothing like this came up.

I’d like to think I’ve been thorough, but am missing something somewhere. It’s sitting in my garage (with the door open!). Do these cars need some specific gas cap, or will just any ventilated cap work? (I can’t imagine it would fail so coincidentally to the overfilling, but stranger things…). It’s a used car, and may not have the original any more.

I hope to avoid resorting to a pro mechanic ($$$).

Has anyone had this happen? Any ideas?

Thanks in advance!

autoduel

Does the gas cap release pressure when you open it (hiss).
The car creates a vaccuum in the gas tank after driving.
If you don't get a hiss, there is a leak in the fuel tank, filler neck, or cap.

PNWdriver

Thanks - it does indeed depressurize.