sudden loss of mpg, ideas from you

[Scott90]

short and to the point..

car is 94 corrolla, automatic, 1.8 liter 146xxx miles

always got about 300 miles to a full tank, now im lucky to get 200. I thought it was leaking gas, since sometimes i can smell gas when getting out of the car, but ive been under it many times looking for a leak and cant find anything leaking or even anything that smells like a leak, very frustrating.

i checked the plug condition to see if maybe injectors are bad but they seem about right, however i have no idea when last time plugs/wires/basic tune up was done, so im going to do all that this weekend, but i dont think just a basic tune up would make such a sufficient loss in mpg, what do you guys think?

also, i now live in south carolina, and the car did get to experience some cold temps, 15 degrees or so, but idk if that would really cause a problem... just strange because its out of no where doing that, any help or ideas greatly appreciated.

as said earlier, this weekend i plan on doing the basic tune up stuff.



and pit road is that way --->
only post if on topic

[Empire]

do the tune up, it should really help.

also, drop the tranny pan and change the fluid and filter. Made a world of difference on my 97 and I just used the cheap stuff. My car has 275,xxx on it.

also check coolant levels and the fan and the thermostat.
If it can't/doesn't warm up, then the tranny won't ever shift into overdrive and that can suck down gas if you do a lot of 45+ driving.

[Scott90]

ill look into that as well, the tranny shifts into overdrive so that shouldnt be a problem but ill look into it. thanks for the input

[Kirk]

I thought it was leaking gas, since sometimes i can smell gas when getting out of the car, but ive been under it many times looking for a leak and cant find anything leaking or even anything that smells like a leak, very frustrating.

This. You have a leak somewhere. You will NOT smell gas unless you have a leak somewhere.

[Scott90]

Any ideas on where to look/feel/smell? Ive been all over this damn thing.

[1BADP71]

check the air pressure in your tires.

[Scott90]

One of the first things checked.

Just wanna emphasize on the sudden drop, it didnt slowly just start getting worse, one tank i got 300 miles, and next i got like 190-200 to a tank. Gonna mess with it this weekend, kinda sucks when I work all week, kinda limited to time during the week.

[matraca112]

You have to have a gas leak somewhere. You need to get the car smoke tested to find out from where. That is where the put a smoke machine to the fill neck of the gas cap and push in smoke as they then look to see where it is come out from. I dont know if there is a way to make a at home smoke machine to do this at home. But this is where I think you sound try to start looking into.

[Scott90]

^ not a bad idea, but if i go that route ill just put a can of SeaFoam into the tank, that stuff creates so much smoke it definitely would do what your talking about, ill try to use that as a last resort though so I dont piss off too many people with a huge cloud of shit

[matraca112]

lol it does not work like that. it puts pressure into the system. and then you push a botten and it then pushs the smoke in. and it is a small amount of smoke that come out. but it will help find your leak. seafom is just going to clean out the injecters and the full system for you and that is about it. it is not going to show you where the leak is coming from. but just my 2 cents.

[Graves]

o2's? running rich? running really rich could cause a "gas" smell.

[Empire]

did you get the drop on this tank? or have you been through a couple of tanks?

it could have just been bad gas... part of the resin ethanol sucks is that it separated from the rest of the gas. AND it absorbs water, so if you get gas from a station that doesn't have a mixer and/or moisture monitor in their tanks, then you could have gotten a whole tank full of ethanol soaked in water.
I've had it happen to me even here in St. Pete. A seemingly popular gas station, and it wasn't mixed right. One tank, I got 100 less mpg and the car just felt sluggish, the next tank, from a different station, and it was back to normal.

[Empire]

o2's? running rich? running really rich could cause a "gas" smell.

an older corolla with 150k miles, the catalytic converter is shot, so even a little on the rich side would make it smell like gas.

[Graves]

in my old ladys '06 the o2 went bad and it smelt like gas. i think her cat is shot too. nice little rattle in it.

[Alan]

Also check the fuel pressure regulator to see if that shit the bed. Pull the vacuum lines on the regulator and look for gas.