sudden loss of mpg, ideas from you

[*JamReX*]

Has it been going on since? Or was it a one time thing... if you looked it over as thoroughly as you used it could be bad gas.

[Scott90]

Okay made some progress...

its not bad gas, its been like this for about 2-3 tanks now so far.

But i looked over the car today after work, got under it felt around some more, the right side (passenger side) of the tank is wet, and when smelt, definitely is the gas, but now to track down where its leaking from, cuz it must be leaking from somewhere, and then dripping down and just covering the bottom side of the tank. I pulled out the rear seats to open up the fuel pump cover to see if anything was wet up top and it was bone dry, so it must be coming from somewhere else up on the tank, maybe where some hoses go? I am not too sure, I guess I have to find some diagrams of the system and see what goes where and start narrowing shit down. Any ideas now based on the new info?

I just wish I had more time to mess with it, by the time i get home i only have about a hour or so to tweak things before the sun goes down, ill have to fix whatever it is this saturday. damn i wish i was home with my garage/tools lol, parking lot mechanics suck!

Any help is definitely appreciated

[steveyjr1982]

When you "fill" it up exactly how are you filling it up? If you overfill your tank you could damage the evap system by letting fuel get into charcoal canister which would cause the gas smell. MPG drop how ever could be a number of things like a gas leak in the tank itself (split seam or rust) or a very worn cat or just a simple tune up could fix it but I would get under there and do a more thorough check for gas. Let the car idle for a bit then get under it and use your sniffer to locate the strongest smell of gas.

[Scott90]

will do.

and when i fill it i just fill it till the gas station handle automatically stops when its full.

[senor honda]

Some people go to a well lit car wash or park under the brightest light down at the gas station.....
Some people get a thin LED flashlight that can be held in their mouth.....
as long as you are not doing major disassembly.....

some Hondas leak from the side seam where the top and bottom half of the tank are welded together.
-Bob

.................................................. ..... parking lot mechanics suck!
Any help is definitely appreciated

[Empire]

it is a major pain, but I would look to the rubber lines that go down the side of the tank and connect to the hard lines.

Try just getting half a tank and see if you get that same wet spot.

Try a quart tank and do the same.

That would help narrow it down to if it is a tank leak and where it is.

[Scott90]

Well, I got under it today to take a better look at that specific area. The filler neck, lines/return lines, all those are dry, including to where they attach to the tank. Now what i did notice, on the right side (same side thats wet) it looks like the seem (where top half and bottom half of tank meet) maybe have cracked or started to come apart. The entire tank looks nice and clamped shut, except that one part. So that is what I am assuming is the problem. I went and picked up some quick steel which im going to try to see if that is in fact the problem, but I cant apply it till probly tomorrow night, maybe even Saturday, I have to use up some gas, I wanna get it to about 1/4 so I know no gas will mess with the sealant as its curing. Hopefully this works, that would be a great 10 dollar fix lol. If not, a new tank runs about 150 which isnt too bad either but id take 10 anyday haha. I'll let you guys know how it goes/if it works. Appreciate the input.

Also, im thinking maybe the cold weather made the tank crack? like maybe i hit a bump one day in one of the colder days and it just cracked? IDK why it would do that, seems about right though because its been like this for about a month now, and about a month ago we had a freezing week where temps barely got out of the low 30's. Cars were covered in Ice all night and into most of the day.

[Empire]

if it was frozen, then it could have made it brittle so that would support your theory.

But i mean, shit happens. they crack and break. 240 fuel tanks will just get random holes in them. honda tanks will split at the seam.
and that's down here where "freezing" is 68*

[Scott90]

Added the QuickSteele this afternoon to the seem that looks blown out, hopefully that was the issue. The package says it fully cures in an hour but im gonna give it till tomorrow to be safe before I even start the car. I'll fill up the tank and well see how many miles I get. Crossing fingers lol.

[Scott90]

Hmmm, so problem still persists... since filling the car up since I added the quicksteel i just finally ran through a full tank and still only got 200 miles to the tank... there must be a bigger crack or something somewhere on the tank that I just cannot see... back to the drawing board... shit.

[Empire]

Is the tank that much of a pain in the ass to pull?
don't remember which car we are talking about... lol.
At this point, for my car, I would drop the tank, and trace all of the fuel lines, replacing any rubber lines I could with fresh lines from the parts store. The advance around here as that nice fuel line with the blue liner in it. I've always liked that line. Bit more expensive, but you only need a few feet of it.
With the tank out, I'd search the whole thing over. Since I'd probably be pissed off about having to drop the tank and wasting all that gas and all of that, I would probably get a little crazy with epoxy and go over every seem possible. Might even take some 2 part epoxy, go over the seems, then spray the whole thing down with truck bed liner.

EDIT: Actually, in all honesty, if I got to that point, once I dropped the tank, and swapped all of the fuel lines. (and examined the hard lines because they can rust and leak too) I'd end up cutting a hole in the top of the tank. Pretty good size so I could have space to work. Draining it out, maybe splash some diesel in there. Get it all nice and clean and wonderful. Let it dry. Then mix up some 2 part epoxy. They make stuff for the inside of fuel tanks. Can't remember what it is at the moment, I just know it exists. Line all of the seams and bottom and all of that. Set it off to the side, then make a little wooden box thing. line it with aluminum foil so it was all shiny, stick the tank in that, and put my shop lights over it to form a make shift curing box. Let it sit over night. Next day, I probably wouldn't be satisfied that it was totally sealed, so I would mix up some more, and go back over the weak points. Then do the same on the outside of the tank. Get it all cleaned up and hit it with some sand paper, and go over all of the seams with the epoxy. Back in the curing box for another over night. Come back the next day, feeling rather confident that it is sealed, I'd go to work on sealing up the hole that I cut out that I'm not kind of upset about doing because I just realized that I spend enough money I should have just bought a new tank. I'd lay down a few strips of mesh and epoxy those down so the piece didn't just fall through. Then I'd epoxy the seams all around that. Thinking I would kill two birds with one stone, I'd truck bed liner as much as I could and stick the thing back in the curing box. Once it is all set up, I'd coat the whole thing again with bed liner so it looks good. Then let it finish the night in the box. the next day, I'd go to install it back in the car. Get pissed off that it doesn't fit right anymore, and muscle it in anyway. Fight the fuel lines back on where they should be. At this point, being pissed off that I spent enough money that I should have just bought a new fuel tank. I'd get it all together and second guess myself, so I would just let it sit. Maybe go get dinner. I'd work up the nerve to get gas in it. Go get 5 gallons, put it in the tank, start it up. Let it idle for a minute thinking that, that makes a difference. Realize that, that is dumb, get in it and take it to the gas station. Fill it to the very brim. Cautiously drive it home, immediately jack it up and look for any leaks. Be happy that I couldn't find any but still suspect that it might leak, so I'd stuff paper towels and cardboard everywhere that I think it might leak from and let it sit. Check for leaks the next day to see if it dripped any over night. Get pissed that one of the paper towels was wet. Start to pull it apart to realize that it was just a loose fuel line. Tighten it up. Clean up and go for a drive. Put about 100 miles on it, fill it back up and figure gas mileage and hope that it is as good as it should be.
Might not be the best plan of attack and probably way over kill and probably not the best option, but that's how it would play out if I was in your shoes.

[NT_Hardcore]

its prob time to buy a new tank. i kno when the bronco tanks seam went bad, we could do nothing to stop the fuel from leaking.

[senor honda]

LKQ recyclers has about 400 gas tanks. Used ones are cheap.
Pick one that looks good and clean.-Bob

[Scott90]

Empire thanks for the long detailed reply, i appreciate it, and BOB i dont live in FL anymore.

The only thing I can now think of given the circumstances is maybe there is a crack in the tank somewhere I cannot see, im living in an apartment up here so I dont have my garage , and the majority of my tools are back at home, but my last option is gonna have to be to pull the tank, I dont think any of the lines are leaking bcuz its bone dry in that area of the tank, ill pull the tank and see what kinda results I can get from it. if i have to ill just replace the tank to make sure its fine, a new tank is only about 150 from autozone/advance so wont be too bad. this will have to be next weekend though, i just got my wisdom teeth removed yesterday and I dont think ill be up to laying underneath a car this weekend. but next weekend ill try to give it a shot and see what I get, again thanks for help and input everyone.

[senor honda]

Then if you are removing the tank, brake-clean the suspected area,
let dry and then tilt the tank over so you can see if the suspected
area is where it is leaking..........might save $150.......to buy gas with..... -Bob