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Discussion Starter #1
my truck isnt getting all that good of fuel mileage. im only getting about 75 mile per 1/4 tank:$:, it is a 35 gallon tank. that almost all in town. any idea of what it might be? give me your thoughts on what i should do to improve it a bit. oh it is stock for the most part. except its straight piped.
 

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Do you have a fuel pressure gauge installed? If not your lift pump could be shot and your VP is doing all the work..this might hurt your MPG
 

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How is your fuel filter doing?
 

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Discussion Starter #4
i do not have a fuel pressure gauge in. is there any other way to tell if the lift pump is shot? my fuel filter is maybe 700 miles old.
 

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Do you have a fuel pressure gauge installed? If not your lift pump could be shot and your VP is doing all the work..this might hurt your MPG
If its the truck in his sig he doesnt have a VP pump he is a 12V. Have you cleaned all your filters? air, fuel, Ect...
 

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Ok so it has the p7100 pump...how is your air filter? What are the gears in the rear end of the truck? Any smoke on start up?
 

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Discussion Starter #8
air filter is fairlly clean, but i will be switching to the BHAF once i get it ordered. im not sure of the gears, i dont think they are 4;10 cause i only run just over 2000 rpm doing 65-70mph and no smoke on start up.
 

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excess smoke would be indicative of the fuel filter. might need a new one... you should fill out the rest of your signature - ie. automatic or manual, rear end gears, 2 or 4wd, what all mods, that kinda thing. it'll give us a better picture of your pickup
 

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sounds like 3.54 gears, what about blow by? Do you have much blow by?
 

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Make sure your intercooler boots are not leakin, any holes in them, clamps tight around them.


Oh and put some new spark plugs in her that always works. :lol3:
 

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Discussion Starter #12
what is blow by? i have heard of it but never knew what it was.
 

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it's "excess" combustion gases getting past your piston rings. You can get under the engine and there's a black tube pointing towards the ground right beside the block (about an inch and a half hose I think) that will have little drops of oil on it probably... if that thing has excess smoke coming out of it (while it's idling), it might be time for new rings.
 

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Discussion Starter #14
i will check for hole in intercooler boots this weekend. is this also consittered "boost leaks"?
 

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Discussion Starter #15
i have seen that tube. ill take a look at it. do i just feel the pressure being blown out of it?
 

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well not so much feeling the pressure but you can see the smoke come out of the tube.
 

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Do you have stock sized tires ?

Is your Speedometer/Odometer reading the CORRECT #s ?

Get real MPG #s. Fill the tank, reset the Trip Odometer to (0), drive around, fill up, divide the # of Gallons (to fill up) into the Total # of miles driven. This gives you your MPGs.
 

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My mileage went from 14+ to 18+ in two weeks just by using an injector cleaner additive at fill up. I used the STP brand but I am sure they are all similar.
 

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Discussion Starter #20
i have stock tire and as far as i know my Speedometer/Odometer are correct. next time i fuel up i will rest the odometer. is the any specific injector cleaner additive for diesels?
 
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