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2006 5.4l F250 SD

Discussion in 'Truck & Equipment Repair' started by Jaynen, Jul 8, 2015.

  1. Jaynen

    Jaynen Senior Member
    Messages: 302

    2006 5.4l F250 SD Slow Accelleration

    I have a 2006 5.4l F250 SD that has poor acceleration and hardly any power. I find it hard to tow my 4500lbs trailer. On the highway i have no passing power and when i come to a hill its hard to maintain speed and i get random cylinder misfires. Also got a lean code and a misfire under 1000 rpm code. If i park on a hill (truck pointed down) and turn the wheel into the curb the truck stalls. I also get random stalling once a month or so. Anyone have any ideas? Thanks.
     
    Last edited: Jul 8, 2015
  2. seville009

    seville009 Senior Member
    from CNY
    Messages: 736

    Have the plugs ever been changed? If you have ethanol in your fuel, try some ethanol treatment for a few tanks.

    I had both issues in my 2006 F350 5.4l. Did ethanol treatment first and that helped alot. Then started having really bad acceleration/missing issues, which is when the original plugs were replaced. Been running smooth and strong since then.

    I've also been using ethanol free gas.

    I'd try all of that first, as it's the easy stuff and are common problems.
     
  3. Jaynen

    Jaynen Senior Member
    Messages: 302

    Ya sorry forgot to mention I got the plugs replaced and the cats tested. I put seafoam in the gas tank before changing the plugs which made the problem worse.
     
  4. seville009

    seville009 Senior Member
    from CNY
    Messages: 736

    I didn't use seafoam for the ethanol treatment. My mechanic iitually used some concentrated stuff, then I bought some regular ethanol treatment at the store. Try that for a bit. Change your fuel filter too if you haven't already done it. That's all I got.....
     
  5. Jaynen

    Jaynen Senior Member
    Messages: 302

    Yup changed the filter too. One thing i tried was i took the gas cap off and it almost seemed to run better but i could be wrong.
     
  6. jhenderson9196

    jhenderson9196 Senior Member
    Messages: 615

    It's my understanding those 5.4 motors have some intake gasket problems that cause intermittent lean conditions.
     
  7. grandview

    grandview PlowSite Fanatic
    Messages: 14,609

    Non ethanol gas i run it in my 5.4 can't believe the difference.
     
  8. Jaynen

    Jaynen Senior Member
    Messages: 302

    Okay ill check out the intake gasket and look for other vacuum leaks. And ill try ethanol free gas. I have a bully dog programmer that has some 89 octane setting. Maybe no ethanol and 89 octane tune. Thanks everyone for the replies so far.
     
  9. grandview

    grandview PlowSite Fanatic
    Messages: 14,609

    http://pure-gas.org/index.jsp?stateprov=ON
     
  10. Jaynen

    Jaynen Senior Member
    Messages: 302

  11. Jaynen

    Jaynen Senior Member
    Messages: 302

    Well i thought i would yake a look at the MAF and i went to unbolt it and the one bolt was completely loose. Is it possible that could leak air and mess things up there? I tightened it down and truck seems to be running better. Ill know as the day goes on.