poor gas mileage help..

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Mar 13, 2003 | 06:42 PM

Eiyse98ls1

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From: Bay area, Ca

poor gas mileage help..

what can be my problem if ive changed fuel filter,plugs and wires and cleaned air filter...i have 66k on my car now.. can it be my o2's or the fuel injection.. should i get the fuel injection serviced? help please.. im only getting about 200miles to the tank and i should get way more than that..
any help would be great.

Apr 1, 2003 | 01:43 PM

sawedoff

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Re: poor gas mileage help..

<blockquote>quote:<hr />Originally posted by Eiyse98ls1:
 what can be my problem if ive changed fuel filter,plugs and wires and cleaned air filter...i have 66k on my car now.. can it be my o2's or the fuel injection.. should i get the fuel injection serviced? help please.. im only getting about 200miles to the tank and i should get way more than that..
any help would be great. <hr /></blockquote>None of the things you replaced are going to make any difference. If they were the problems you'd be getting other things. You didn't state if you had done any modifications to your car. If you're getting that kind of mileage, then it's not a restriction in your fuel system. You're getting too much fuel. It's not an O2 sensor, because you'd go into limp home mode, and there wouldn't be this going on. I will bet that it's your fuel pressure regulator, or you may have a bad injector bank or a single injector leaking too much fuel into the chamber. Check your wiring harness. Is your computer throwing any codes. Have you had your ECM tuned by anybody? They may have screwed up your ECM. Check your regulator and fuel injectors by the manual.

Apr 1, 2003 | 02:32 PM

Str8crusinT/A

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From: Oklahoma 1000+ posts from LS1.COM and 430+ posts from WWW.COFBA.COM

Re: poor gas mileage help..

are these highway or city miles... I get only about 180 miles in the city. But I don't drive like a grandma.

Apr 1, 2003 | 03:12 PM

Nitrous Assisted

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From: 200 MPH

Re: poor gas mileage help..

200 per tank?!? i would be excited if i got that. i usually get 150-180 per tank, thats all city and <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" /> at every light <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

Apr 1, 2003 | 03:36 PM

FrankSS

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From: Clarksville, TN

Re: poor gas mileage help..

I had that problem too. When I put on my LT's and no cats, the COT in the computer i guess was puttin too much fuel in the car. It was so bad that you could be sittin in the car with the windows up and your eyes would be watering, and i went like 75 miles on half a tank of gas. I went into Edit and turned off the COT, and now i get like 300 or so per tank (depends on how heavy your foot is too) <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" /> <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" />

Apr 1, 2003 | 06:40 PM

Eiyse98ls1

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Joined: Jan 2003

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From: Bay area, Ca

Re: poor gas mileage help..

<blockquote>quote:<hr />Originally posted by sawedoff:
 <blockquote>quote:<hr />Originally posted by Eiyse98ls1:
 what can be my problem if ive changed fuel filter,plugs and wires and cleaned air filter...i have 66k on my car now.. can it be my o2's or the fuel injection.. should i get the fuel injection serviced? help please.. im only getting about 200miles to the tank and i should get way more than that..
any help would be great. <hr /></blockquote>None of the things you replaced are going to make any difference. If they were the problems you'd be getting other things. You didn't state if you had done any modifications to your car. If you're getting that kind of mileage, then it's not a restriction in your fuel system. You're getting too much fuel. It's not an O2 sensor, because you'd go into limp home mode, and there wouldn't be this going on. I will bet that it's your fuel pressure regulator, or you may have a bad injector bank or a single injector leaking too much fuel into the chamber. Check your wiring harness. Is your computer throwing any codes. Have you had your ECM tuned by anybody? They may have screwed up your ECM. Check your regulator and fuel injectors by the manual. <hr /></blockquote>no big mods at all.. lid, cutout, suspension, 18's, bear rotors, shock tower, pro5.0 w/ lss and thats about it..my computer isnt throwing any codes. i had a freind scan it and no codes were showing, he said everything seemed fine but timing he said was at 20 something?is that normal..havent had ecm tuned.. im note mechanically inclned so what wiring harness are talking about in the engine bay? and how would i check the regulator and fuel injectors by manuel?
thanks for the info.. hope those are the cause of my problem..

[ April 01, 2003, 06:42 PM: Message edited by: Eiyse98ls1 ]

Apr 1, 2003 | 07:29 PM

Eiyse98ls1

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TECH Regular

Joined: Jan 2003

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From: Bay area, Ca

Re: poor gas mileage help..

<blockquote>quote:<hr />Originally posted by FrankSS:
 I had that problem too. When I put on my LT's and no cats, the COT in the computer i guess was puttin too much fuel in the car. It was so bad that you could be sittin in the car with the windows up and your eyes would be watering, and i went like 75 miles on half a tank of gas. I went into Edit and turned off the COT, and now i get like 300 or so per tank (depends on how heavy your foot is too) <img border="0" alt="[burn out]" title="" src="graemlins/gr_burnout.gif" /> <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" /> <hr /></blockquote>what is COT by the way?another possible solution