Hi Everyone.
This is my first post. I have a 1990 4runner SR5 with a V6 automatic and 120K miles. It's in good shape but gets terrible gas mileage (11 MPG city and 18 MPG highway.) At $3.25 a gallon it hurts. I recently developed a gas leak under the gas tank but only when I completely fill the tank. I removed the gas tank skid plate and could only see gas slowly running down the side of the tank either from the tank seam or the top. I can't tell which.
I checked the filler hose and it looks fine. Does anybody know if I can I get access to the top side of the tank by cutting a hole in the floor under the passenger side back seat? It doesn't seem to be a metal floor but some kind of a fiberboard cover over the tank hose and wiring connections. Before I drop the tank I want to check the topside hose connections. Maybe the leak is there. Thanks.
$Bill
Danbury

There's an access panel in the back to get to the fuel pump, you can see some of the tank top from there.
It's possible it's rusted thru where the tank sits against the frame rail.
Rust thru the frame rail right there is real common.

Hi Fourdw1,
Thanks for the reply. Where is this access panel? Is it in back of the passenger rear seat in the cargo area underneath the carpet? The only place I could find was under the rear seats. It looked like some kind of heavy molded fiberboard that was painted over at the factory.
$Bill

Can't help ya with the tank. Might just need to drop it and see where the problem is.

The 3L V6 engine is a dog of an engine. Combined with an auto tranny and with extra weight of the 4runner body, the mileage you are getting is about on par. I have a 4x4 truck with the 5speed and get about the same.