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Discussion Starter · #1 ·
**update** Mpg

i know there has been threads before on mpg. but i'm lazy and don't want to search through them........sorry :think: ive got a flowmaster, k&n airfilter, drive conservatively and running stock 245's right now. in the city im busting out a whopping 10.4 mpg. btw, ive got a hoe with a 350 in it. would changing the plugs, cleaning the injectors give me any kind of mpg boost? or anything at all? thanks in advance
 

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NCOR
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10.4 driving conservatively with those mods and 245's...ouch. I get 12-13 with 33's and 3.73 driving like a teenager with very similiar mods. I would suggest changing your fuel filter if you haven't done it in the last 15,000 miles, also plugs that have to big a gap could give you incomplete combustion resulting in bad gas mileage. So in other words if you running $2 copper plugs just replace them with new copper plugs(gapped correctly of course). There are others but those are my immediate thoughts.
 

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Discussion Starter · #3 ·
does anyone know where the fuel filter is? is it hard to get to/ replace? price? the plugs haven't been changed in god knows when (more than 50,000 miles im sure)as well as the fuel filter.
 

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NCOR
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350 vortec fuel filter should be in the driver side framerail under the driver seat. I just did mine this weekend. Not to hard, just be prepared for a 1/2 of gas to spill. The plugs should be changed too...they need them after that long. The fuel filter just needs a socket set to remove the plastic peice (slide back off of it, do not try to pry it forward) and two cresent wrenches to unscrew the lines, took me 40 minutes having never done it before. Mine was $7 at Autozone.
 

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Discussion Starter · #5 ·
good deal..........i just might have to do that this weekend. when im driving on the highway i can get 15-16 mpg, but the city i haven't topped out over 10 yet, i know more stop and go means bad mileage, but not this bad......its pissing me off :nono:
 

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Yeah somethings wrong, I think a tuneup would be in order. I recently achieved 15 mpg with mostly city driving, with 166,000 miles, TBI 350, 3.42 gears, and 285/75/16. Its all in the foot, the slower the acceleration, the better your mileage gets. Although I havn't totally proven this yet, I made quite a few WOT 0-75 runs on that 15 mpg tank :crazy:

BTW, is your SES light on?

how old are your o2 sensors?

Definitly pull your plugs and have a good look at them. Eventually they will get all nastied up. I run mine (cheap copper delcos) about 2 years a set, along with wires/cap/rotor. About halfway through I'll pull them all and clean them off real good, seems to help, esp on an old motor.

I also try to run some injector cleaner every once in a while, (usually when I think of it), I'm not entirely sure how much good it does, but for like 3 bucks a pop, can't really go wrong.
 
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I would say do the fuel filter, change the spark plugs, and change the wires. I have 35's 3.73's flows and a decently fun right foot (since getting tips installed) and I get 12-14 with mostly city driving.
 

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Plead The First
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You might also try synthetic oil. I know mine reponds better to it, though it's the newer ls1 generation engine.
 

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Discussion Starter · #10 ·
alright, this weekend im going to change my fuel filter, new plugs, new wires, change my oil (im already using synthetic), my 02's could be out, as far as i know they have never been replaced. my ses light does come on but i have no clue why. dumbasses up at auto zone said it had to stay on constantly before they could run a test on it. when i first got my hoe, it came on when i came to an idle, my caty was f-ed up so i thought that might be the problem. now i am running no cats, light still comes on when idling.......so i dunno there. i'll also clean the k&n too, not sure when the last time it was cleaned either. and ill throw in a batch of fuel injector cleaner next tank. right now its not a huge issue because i'm running what i like to call RPD Petroleum (girlfriends dad's initials, i have his gas card and can use as pleased.......his gas bill for the month is around 2 g's, so mine is minor to him) how much are 02's?
 

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If its a vortec, alot. :D I bought my last O2 off ebay for 30 bucks. Dunno what they are at the store. I'd definitly get your codes read by someone that knows whats up, all kinds of things could be out. If you have no cats, and no o2 simms, your rear o2 sensors are probably going nuts, which won't help.
 

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Discussion Starter · #12 ·
i got everything done properly when i had the cats removed.....the ses light came out before i removed them, and come on now just as often :think: confusing...........ill try to take it up to autozone sometime....hopefully the wont be a bunch of bastards and tell me they cant do it since my light doesn't stay on all the time :guns:
 

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If its a vortec removing the cats could potentially hurt mileage. Backpressure is need and I realize you have 40 series, but the combination of no readout from rear O2's and less backpressure could be loosing you a lot torque...which is bad for city driving.
 

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agreed. the loss of backpressure could hurt your mileage. you need rear O2 sims, other wise you are not running with the correct A/F ratio. last i remember hearing is that you run rich in this case.......
 

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Discussion Starter · #15 ·
ive got rear o2's.......gas mileage was just as bad before i removed the cats :think:
 

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Damn, I thought I found it. All right well try the maintenace things, including cleaning the airfilter and then me know. Im sure those will help.
 

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Discussion Starter · #17 ·
alright........thanks guys......i'll try and do some of this shit this weekend.......first home game so ill be busy saturday watching some football, probably watching us get our ass kicked but who knows.....ill work on it sunday.
 

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Discussion Starter · #18 ·
ok.........went to autozone today and got:

ac-delco oxygen sensor
ac-delco plugs
ac-delco plug wires
distribitor cap
k&n recharger kit
fuel filter
some quaker state synthetic 4x4 oil (about time to change anyways)
fuel injector and carb cleaner

cost me around 130 bucks.......hope to hell this solves my damn problem
 

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Discussion Starter · #20 ·
DirtyBlackZ71 said:
never heard one good thing about quaker state oil man.
no shit.....maybe i ought to change....what do u run?
 
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