3800 poor gas milage

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i just installed a digital dic in the gt and it shows that i am getting 16.5 mpg. I figured it out on the calculator and it is about right. I do all city driving , the car has 87000 miles on it and a few mods like exhaust k&n filter plugs wires and such. Is this normal or crappy gas milage?
 

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Originally posted by Fish@Apr 4 2005, 11:17 PM
Id say pretty crappy. How old are the plugs and wires?? Have you changed your PCV valve? How do you drive. It all effects your gas mileage.
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I try not to drive on it hard because of gas, plugs wires pcv valve fule filter is all less than a year old. Also i got a intense pcm and i use V-power gas and my gas milage has not changed.
 

Fish

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Hrm, thats wierd. What kind of plugs?? What are they gapped at?? Maybe do a scan with your IPCM. I know with my DHP, AL 605 with a .058 gap, 6 month old wires and almost 2 years old PCV I am getting 18.9 miles on the DIC, and I calculated it at around there as well.
 

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Originally posted by Fish@Apr 4 2005, 11:38 PM
Hrm, thats wierd. What kind of plugs?? What are they gapped at?? Maybe do a scan with your IPCM. I know with my DHP, AL 605 with a .058 gap, 6 month old wires and almost 2 years old PCV I am getting 18.9 miles on the DIC, and I calculated it at around there as well.
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they are ngk plugs, i believe tr55 i cant remeber off the top of my head. They should be gapped at .060 I have had my car hooked up the the Genissis computer at school in electrical class and i remeber it said i was running rich.
 

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Originally posted by Fish@Apr 4 2005, 11:49 PM
Running rich can be bad for gas, since your using more of it. I usually though raising your gap would make you run more lean, but Im not totally sure. Plus if your already at the stock gap with the plugs, cant really go any higher.
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humm maybe it is time to change the o2 sensors. Also when i was crusin down to texas i was gettin like 32ish miles per gallon, so the highway part isnt bad.
 

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Originally posted by emersonhart13@Apr 5 2005, 04:51 PM
Fuel Filter, MAF (From over oiling your KandN if you have one), or dirty injectors?

Any of those?

P.S. Someone needs to make a sticky/how to post on fuel economy these days!

John
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my car has been like this scince i bought it, 2 years ago, i have never been able to figure the poor gas milage out.
 

3800SC98

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Originally posted by 2000gpgt+Apr 5 2005, 06:25 PM-->
<!--QuoteBegin-emersonhart13
@Apr 5 2005, 04:51 PM
Fuel Filter, MAF (From over oiling your KandN if you have one), or dirty injectors?

Any of those?

P.S. Someone needs to make a sticky/how to post on fuel economy these days!

John
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my car has been like this scince i bought it, 2 years ago, i have never been able to figure the poor gas milage out.
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[/b]

Have you cleaned the injectors?

I'm having a similar problem with my 98 (13-14MPG), I changed the fuel filter and it didn't seem like it was clogged-up or anything. The fuel that came out of the filter did seem dirty, very dirty. I might have my injectors cleaned just to make sure, but I think I should scan the car just to see what my IPWs are and all that good stuff.
 

smug

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Have you cleaned the injectors?

I'm having a similar problem with my 98 (13-14MPG), I changed the fuel filter and it didn't seem like it was clogged-up or anything. The fuel that came out of the filter did seem dirty, very dirty. I might have my injectors cleaned just to make sure, but I think I should scan the car just to see what my IPWs are and all that good stuff.
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I have used the chevron injector cleaner but never professional cleaned with the good stuff. Also what about a dirty engine? Should i try the decarbon kit thing the gm sells?
 
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