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F350 V10 Running Poorly

I need help! My 1999 F350 V10 6.8L is sputtering, backfiring, and lagging at low speeds and when taking off. Once I get above about 15-20mph it smooths out and runs perfect. Sometimes it even makes the tranny jump and shift hard. If I turn it off and then back on it will usually fix the whole problem. I just had the transmission serviced, the gasket between the tranny and transfer case replaced, oil is clean, replaced EGR valve, EGR vacuum solenoid, DPFE, Cleaned air intake system including MAF sensor, replaced fuel filter, and replaced vacuum lines to PCV valve. I have no idea what is causing it! It has no check engine lights. The olnly lights I have had are speed sensor, and EGR low flow. Both are gone now.

Any ideas?

Thanks,

James from Texas
 
Hard shifts, as well as sluggish starts

I'm having the same issue as James with rough running engine and hard shifts. I also have a 99 F350 V10.

I don't get backfires, but everything I have. Here are the symptoms:

- sluggish starting, mostly if I have my a/c turned on. If a/c is not turned on it usually starts right up.
- The tranny gives hard shifts. It only occurs per driving "session". If I turn off the truck and back on, it will usually work fine after that. But if it gives one hard shift, it will hard shift every time until I shut off and restart the truck.

I replaced all coils and plugs and that made things run more smoothly, but it still hesitates some when trying to accelerate from being at a complete stop. The EGR and MAF seem fine. I'm not sure if the sluggish running and the tranny hard shifts are related or not. Any guidance would be appreciated!
 

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