Major problem with hesitation/bucking..

[mschn99]

sounds to me like some of you guys arent draining your drain valves in your fuel water seperator. Your supposed to drain that monthley. Its going to affect the 6.4 way more than any motor prior to it with the common rail injection....

[bleedsblue]

I don't believe it's water in the fuel. Mine happens only when the truck should be downshifting. If I'm leaving a stop light and roll into the throttle it's fine. If I'm on the freeway and get on the throttle a bit to pass someone it's okay but if I go 3/4 throttle or so at that point the truck should downshift it instead bogs down and smokes like it's loading up on fuel.

Bill

[2highten]

before you start on water or poor fuel you need to drive one of these. My truck is a manual trans and when you slow for a turn or to aloow someone else to turn and then go to accelerate you may not seem to go at all and then it bucks and jerks terrible , if you step on it agressivly it won"t do it. I just ran a 1300 mile trip with my 5th wheel flat bed, weighted in at 23000 lbs gross and it performed well but fuel milage is poor 10.4 mpg. I think it would get better mpg with a 4.10 axle ratio. I am working with a fuel programer to try and come up with a better set up to overcome the jerks and bucking .

[WOOL-PULLER]

my 6.0 will do that too. think its normal. if your over 40mph and you start laying into it when the convertor is locked before it kicks down a gear it will load up and blow black smoke

[Gabriel71]

I basiclly have the same truck and does the same thing. I took it to Ford and they reprogrammed the computer. It seemed better for a while but back to the same thing now. Fuel milage on mine is extremely poor 7.5-8.5 towing and 12.5-13.5 highway. I think my '04 6.0 had more power and definitely better fuel economy.