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NEED HELP!! My 300 gets 3mpg!!!

Discussion in 'The Hokey Ass Message Board' started by "T'RANTULA", Feb 5, 2012.

  1. william.ali.kay
    Joined: Nov 20, 2009
    Posts: 824

    william.ali.kay
    Member
    from Milwaukee

    Id suggest a vacuum gauge to see if something is going on with the fuel while driving.

    Have you changed/fixed anything lately like gas lines, gas cap, fuel pump,etc,,, anything like that?
     
  2. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    I have ran outta gas several times and after wards looked for leaks and felt for leaks. Ill keep lookin and hopefully find the problem
     
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 55,942

    squirrel
    Member

    [QUOTE="T'RANTULA";7421629] do have a couple bad lifters in the engine but I dont think that could cause this problem?[/QUOTE]

    What is the vehicle? If it's an OT vehicle that has a catalytic converter, see if it's plugged
     
  4. Dayzedandkonfuzed
    Joined: Oct 20, 2011
    Posts: 86

    Dayzedandkonfuzed
    Member

    Hate to sound like a broken record, but when they're right, they're right. There's no way you could stuff that much fuel through that carb, and even if you did it wouldn't run.

    I had a dodge shadow once that had rotted fuel lines. Most of the time it would siphon air into the line rather than leaking, but when parked on the right embankment (and probably when driving on the right embankment,) it leaked about a quart per minute.
     
  5. BobF
    Joined: Dec 30, 2004
    Posts: 232

    BobF
    Member
    from Poway, CA

    Are you basing this on speedometer odometer? Is it correct? I agree with several others stating it would barely run at truly 3MPG.
     
  6. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Dosent have a catalytic converter
     
  7. Cutlassboy68
    Joined: Dec 3, 2011
    Posts: 593

    Cutlassboy68
    BANNED
    from Boone, Nc

    [QUOTE="T'RANTULA";7421629]I just pulled the plugs and the motor is still hot. The plugs are a blueish white color but not black. I got a new gas tank with new fuel line and ive dissassembled the bed and looked every were for 4 months and i cant turn up a leak. This just seems to be insane! I do have a couple bad lifters in the engine but I dont think that could cause this problem?[/QUOTE]


    Sounds like your running lean also... Deffinalty have a leak somewhere.

    I would suggest starting it, blocking both the front and back tires, crawling underneath it and following the gasline from the tank to the carb...
     
  8. Or else some other meathead was putting gas in the tank when no one was looking. :eek:

    That is pretty damned drastic a change to heppen over night and not have any other symptoms. Even @ 16 that thing wasn't doing too well in the mileage dept.
     
  9. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Thats what I dont get, the odometer has rolled over a bunch cause the motor is at 419k miles but I have to fill the truck up 3 times a week!!!!
     
  10. Dayzedandkonfuzed
    Joined: Oct 20, 2011
    Posts: 86

    Dayzedandkonfuzed
    Member

    i'd start by investing in a locking gas cap
     
  11. jazz1
    Joined: Apr 30, 2011
    Posts: 1,534

    jazz1
    Member

    I got the same engine ,,85 f150 4x4 300 4sp,,it was getting 6mpg and it ran great.. Problem was the "diaphram" was ruptured causing fuel to flow all the time out that little tube in the throat of the carb so if you look down the carb at idle you should not see any fuel. The diaphram is not included in most rebuild kits,,it was not in mine. Also check your choke tube. My choke tube was not connected,,,could not tell with my good eye but the choke would open while idling in the driveway but then close when I got going down the road and that sucked the fuel...both of these problems will have a significant impact on fuel mileage.

    excuse me for not knowing the proper names for the parts in the carb
     
  12. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Ill try that but Im skeptical
     
  13. Is the speedo right? Have the trans, rear end or the tires changed?
     
  14. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Before I rebuilt the carb the diphram had ruptured and I had thick black smoke comin out the exhaust. I got a manual choke and after the truck warms up I open it all the way
     
  15. roundvalley
    Joined: Apr 10, 2005
    Posts: 1,776

    roundvalley
    Member

    Two dumb questions: are you filling up out of a farm tank and can you seee the gas tank to make sure it is not collapsed?
     
  16. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Same tires and the speedo is really close, SORRY FOR THE GUESSING GAMES but it has me stumped
     
  17. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Whats a farm tank? :confused:
     
  18. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,418

    Von Rigg Fink
    Member
    from Garage

    Does the engine seem like its working real hard to get down the road..like its hauling a heavy load?

    check after a good run, Is the trans too hot?
    is the rear end too hot?

    just some things that might be loading up the normal rolling resistance of your drive train..
     
  19. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    The funny thing is my rear end was a posi and now I only got power to the left wheel
     
  20. henry29
    Joined: Sep 5, 2007
    Posts: 2,873

    henry29
    Member

    [QUOTE="T'RANTULA";7421693]Thats what I dont get, the odometer has rolled over a bunch cause the motor is at 419k miles but I have to fill the truck up 3 times a week!!!![/QUOTE]

    Your spending $670 a month on gas?
     
  21. Dayzedandkonfuzed
    Joined: Oct 20, 2011
    Posts: 86

    Dayzedandkonfuzed
    Member

    [QUOTE="T'RANTULA";7421715] I got a manual choke and after the truck warms up I open it all the way[/QUOTE]

    By that you mean you push the knob in all the way, right?
     
  22. roundvalley
    Joined: Apr 10, 2005
    Posts: 1,776

    roundvalley
    Member

    Farm tank= a home tank with a metering nozzle. in other words; how much gas does it take to fill it up when you run out?
     
  23. jazz1
    Joined: Apr 30, 2011
    Posts: 1,534

    jazz1
    Member

    So you have the choke tube plugged and are running a manual choke..That's what I did also. Do you see any fuel coming out the little tube in the carb at idle.."acceleration pump" that's the name of that diaphram!
     
  24. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Some were like that but I dont drive it anymore til i figure this out
     
  25. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    Yes
     
  26. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    No fuel comes outta the little tube unless you put the pedal to the floor
     
  27. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 661

    "T'RANTULA"
    Member
    from Ohio

    13 gallons of gas
     
  28. Dayzedandkonfuzed
    Joined: Oct 20, 2011
    Posts: 86

    Dayzedandkonfuzed
    Member

    What did you do to the car around the time the mileage dropped off? Is that around the time you rebuilt the carb?
     
  29. Rickybop
    Joined: May 23, 2008
    Posts: 9,606

    Rickybop
    ALLIANCE MEMBER

    [QUOTE="T'RANTULA";7421726]...SORRY FOR THE GUESSING GAMES but it has me stumped[/QUOTE]

    Don't be sorry. We like guessing games...lol. Kind of interesting.
     
  30. Dayzedandkonfuzed
    Joined: Oct 20, 2011
    Posts: 86

    Dayzedandkonfuzed
    Member

    x2!
     

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