poor gas milage question

hi guys ,
im driving a 1992 civic sedan
ive been getting horrible gas mileage. could this be because of my header missing a bolt. it is on the lower far right of the header.
also im missing a vacum line from some device that is directly under the fuel filter(dont know what it is?) please help.

Just an educated guess, but i think it would be the line more than the bolt. But things like tire pressure, air filter, and spark plugs can also have a great effect on gas milage.

well i dont know what that device is called can anyone help me name it.
it is located on the passenger side firewall under the fuel filter. it has two hoses and a vacuum hose. 92 civic sedan

LoL how cool is this. I have a 92 sedan also and have SHITTY Mileage!. Ive asked this question many times and asked several mechanics but no one can really help. well.. A honda dealer said I should get a valve job done. my car just hit 100,000 miles and they say its time. I'd do it if it helps but, if it doesnt, screw it. (I'm getting used to this LInux 9.2 operating system) Me I'm getting like 220 miles to the entire tank. It sucks when I met someone eho had a 93 civic with 272,500 miles on his car and was getting 380 miles to the tank!!! WTF!?!?!? :mad: :mad: :mad:

eureka i think ive found it, i was looking thru y helms manual. it is called a charcoal filter. it recycles gas vapors by use of manifold vacuum. the damn thing wast even plugged into the vaccum line. so now i have the feul pressure regulator, the charcoal filter, and the sensor that is attached to the backside of the intake manifold, all running off of one vacuum line with a bunch of T connectors. plus im about to change my sparkplugs and oil. last tank i got 17 mpg. after making all these changes and reset ecu plus advance timing (without a light) i got 20 miles without the damn gauge moving when i get to 40 miles ill calculate and see the difference

ok didi it change spark plugs change oil reattached vacuum to charcoal filter. reconnect purge solenoid. retarded timing. i got 30 mpg on 1 gallon of gas.alos accelreation has improved dramatically.
heres the good part my freekin muffler came completely off yesterday. my car is so freakin loud now. sounds like an after market muffler. anyway. dude check your charcoal canister make sure it getting vacuum. if not it will really mess up your mpg.

I see a bunch of hoses connected to it but could something be wrong with it though? If I take it off, can I take it apart or something? Just to see if its clogged or something. How much is a new one and would it help to change it? Do they ever have to be changed? I'm talking about the charcol canister thingy. Thanks

Just an educated guess, but i think it would be the line more than the bolt. But things like tire pressure, air filter, and spark plugs can also have a great effect on gas milage.


so that brings up a question that has been in the back of my mind......does a new ram air cold air intake kill your gas mileage...i mean if its being cleaned and serviced regularly does it still kill your gas mileage???help would be appreciated

actually, a CAI would help your gas mileage in theory. Your engine never burns up all the gasoline that is sent to the cylinders. Giving it a denser intake charge will help burn more of the gas that is sent into the cylinders, so you should be getting better mileage.

Driving habits will also make a difference. My 2000 civic sedan will get 35-37mpg mostly highway at around 65mph. But when I'm going around 80-85mph, once again on the highway I'm lucky to get 30-31 mpg.

But on another note, my friend and I went on a trip over the summer, taking his 94 civic CX hatch (manual), but it had a rebuilt DX engine (with DX manifolds) , but the old CX trans in it. That stupid car would get consistantly in the mid 40's. I can't figure out how that works.

Please help me with the canister thingy. Can I check it out to see if its fine? I'm getting about 19-21 MPG! :banghead: wait... if I get 220 miles to the tank, how many MPG am I really getting? honda dealers keep telling me I have a 13 gallon tank but here they say 11. Which is it? lol. Thanks all. And please help me with any ideas that can improve my mileage. All I do is drive and its killing me. My explorer gets beter mileage! Would replacing the canister help? more details! :smokin:

the civic has a 11.9 gallon tank. So 12 essentially. I was getting about 220-250 mile to the tank in my 4th gen too. so you are getting about 19-21 mpg. Maybe you need a tune up

i have a '95 ex auto and i only get around 220-250 also i normaly fill up aroung 230 because my guage says my car has no gas what so ever... so i have the same question... WHY O WHY am i geting sucky MPG!!!! cuz 18-20 mpg sucks mad ***. like my stars hu LOL.. i want the 30-40 mpg that honda says i should get. please help us all!!!!

Okay, this is a complete stab in the dark, but it's worth mentioning. My father has a 84 Camry (orignal owner). I know it's not a Civic, but hear me out. I remember several years ago (like 5 or something), he was getting just AWFUL gas mileage. He couldn't figure it out. We'll, he doesn't use the greatest qaulity gas in the world. His machanic suggested he probably had sludge in the tank from the crappy gas he used. He has the tank drained and cleaned, all the sludge on the bottom of the tank removed. His gas mileage improved a bunch, as that was a big part of his problem. I'm not saying this is your problem (you never know what kind of gas was put in it from the previous owner though), but I thought it was worth mentioning. Ona side note, so what did he do within a few years? He started not paying attention to qaulity of gas an just getting what was cheap (arco, astro, etc). Go figure, huh?

damn do you thihjnk it could be cheep gas.
ive been living on cheep gas for like 6 months. it dosent even have aname brand.

damn do you thihjnk it could be cheep gas.
ive been living on cheep gas for like 6 months. it dosent even have aname brand.

Well, I don't know if that's the sole cause, but cheap gas certainly isn't helping anything out, lol. Remember, not all gas is created equal.

Actually if it's too cold out a cold air intake will kill MPG. The sensor that you put into the intake will be cold all the time and hence always think your car is NOT warmed up so it will run rich alot more.

Cheap gas can definetely degrade your mileage. Its like buying a Hyundai to save $$. But then you never have a car because its always in the garage costing you money one way or another. Careful where you go cheap cause its likely to cost you more dough anyway.

yo djsire i need to know about this charcoal filter thing. i looked on my passenger side under the fule filter and there is this long roind black tube thingy... is that is?? there is also a tube sticking up right next to it not attached to anything it's just sitting there. need help plz