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gas mileage

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Old 11-25-2002, 01:06 AM
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Colder air is more dense. More air detected by the MAF delivers more fuel to keep the AF ratio correct. I don't think it should be THAT bad, lead foot.

Get some lighter shoes.
Old 11-25-2002, 01:15 AM
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I get awful gas mileage, but of course im a 17 yearold, so u know I got some lead feet. But my question is does anyone else have gas gauge problem, Mine lies to me and is sometimes off as much as a quarter tank, It changes before my eyes, its nuts! I understand GM had a problem with the gauges, least thats what im told, but how can i fix this and whats it gonna cost my broke @55
Old 11-25-2002, 02:04 AM
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Originally Posted by willwren
Colder air is more dense. More air detected by the MAF delivers more fuel to keep the AF ratio correct. I don't think it should be THAT bad, lead foot.

Get some lighter shoes.
I'm telling you, I did a substantial amount of highway driving @ constant speed on that last tank (probably about half a tank'* worth) I don't care HOW dense the air is here in Central NY, I shouldn't be getting 17mpg. My VAN got that much in combo driving (that was a 3.3L.)
It'* time to do some maintenance, methinks.
Old 11-25-2002, 04:28 AM
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My first suggestion to anyone with 50-60,000 miles and a fuel mileage prob would be to change the O2 sensor(*). My mileage dropped SUDDENLY by about 7mpg back in late July. A couple people suggested the O2. I put a faulty from the factory O2 (aftermarket) in, and the mileage still jumped up by 5! Went up again when I ditched the thing and went AC Delco.

Looks like the lifetime on stock OEM O2 sensors is about....well, anywhere between 45k and 70k from what I've seen. I'm basing that on a small sample size of about 5 cars. If it doesn't fix it, don't worry. It'* a consumable part and would have failed soon anyway!

I have yet to see a MAF sensor fail without throwing a code, but the O2 doesn't always throw one. It and the PCM think everything is cool while it gets old. Your mileage is what suffers, and you probably won't throw a code til the thing goes completely kaput.
Old 11-25-2002, 08:58 AM
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Originally Posted by Bonneville_blue
I get awful gas mileage, but of course im a 17 yearold, so u know I got some lead feet. But my question is does anyone else have gas gauge problem, Mine lies to me and is sometimes off as much as a quarter tank, It changes before my eyes, its nuts! I understand GM had a problem with the gauges, least thats what im told, but how can i fix this and whats it gonna cost my broke @55
Heh, I'm 17 too, and I tend to be a leadfoot also. My gas gauge also plays games with me. It moves very slowly for the first half of the gauge, and then on the last half, moving toward empty, it moves very fast. I don't know what is up with that.
Old 11-25-2002, 10:03 AM
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Originally Posted by willwren
My first suggestion to anyone with 50-60,000 miles and a fuel mileage prob would be to change the O2 sensor(*)....

Looks like the lifetime on stock OEM O2 sensors is about....well, anywhere between 45k and 70k from what I've seen. I'm basing that on a small sample size of about 5 cars. If it doesn't fix it, don't worry. It'* a consumable part and would have failed soon anyway!
Bill, I've got another symptom besides the fuel economy that might indicate a problem - when I start my car, cold OR at operating temp, the engine seems to "hunt" for an idle for the immediate 2-4 seconds after I start it (i.e. the engine doesn't "roar to life" so to speak). It doesn't hunt around after this time, but it still doesn't sound normal - at least not for any previous car that I've owned. When I start a car, it should turn over and fall right to its idle.
Personally, I was thinking of either the plug wires or *gasp* a fuel pump problem, but maybe you can speak from experience.
My first remedy might to disconnect the battery and flash the computer and see what happens. Hell, it used to work with my POS Chrysler....
Old 12-02-2002, 12:07 PM
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I talked to someone I know about my poor mileage and he asked if I had a fuel leak. When my car is parked it dosn't leak. There are never any fluids under it in the morning when I go to work. Is it possible some fuel could be leaking only when i drive the car?? He told me I should change the fuel filter. I bought a new one a couple months ago but haven't had a chance to get it installed. Could this be causing very poor mileage (in addition to the O2 sensor...) He also mentioned something about the fuel pump and too much pressure or something. Does that sound like a possible problem? Where is the fuel filter in a 94? Thanks for the help!
Old 12-02-2002, 12:48 PM
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the fuel filter is underneath the car on the right side underneath the right rear seat. It is really easy to see and easy to install. You may want to install a new o2 sensor for better fuel economy. Cleaning out your TB may also help as well as a new pcv valve. There are a number of things that affect gas mileage. I have the same problem on my 94 and i am working to replace a bunch of things to help fuel economy. I think I finally got it though. I should be averaging about 350 miles to a tank now. Alot better than before.
Old 12-02-2002, 01:06 PM
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My friend has a 94 SE w/ 150K miles and gets a bit over 350miles to the tank also. I think the maximum I ever got was 275. Last week for some reason I got 230. Where'* the pcv valve and how easy is it to install? Thanks for the help. I'm actually going to change the O2 sensor when I get my wheel bearings replaced.
Old 12-02-2002, 01:13 PM
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I dont think you have a supercharger right? My pcv is on the supercharger labeled pcv. It shouldnt take too much hunting for you. Its really easy to install and right on top of the engine. You can actually test the pcv to see if its still operational. Take it out, wherever it is, and shake it. If it rattles, its still good. You may want to think about heading to autozone and picking up a basic car manual such as haynes. Good luck.


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