Question about Ford F-250

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My 390 is idling poor after its warmed up at idle. Mileage is way poor

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  • vbinder3313 Aug 13, 2008

    Thanks jigsawbill had it rebuilt and runs great

  • woofwoof1025 Apr 16, 2009

    My 390 seems to run ok, the milage is guessed at about 11 mpg.   It should be about 15 from what I understand The idle is too fast even when warmed up.  As long as I drive 55, the truck humms down the road.  How can I adjust the idle down, or is it advisable?  It backfires when very cold until warmed up.  Was told  by previous owner that the carburator was warped, but I dont think she knew what she was talking about.  Was also told by someone else that the engine was prone to valve problems and to sell it  before they become a problem.  Would like to keep the truck (it was a gift) and dont know what to do.  Anyone know?



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I presume you have a carburetor, if so it is time to replace it. There used to be kits to rebuild them, but the kits available today just don't get the job done. Sounds like you have a dirty carb, and of course this is somewhat complicated to remove and take apart and clean. There may even be a rebuilt available for it.

Posted on Aug 06, 2008


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