Tranny or Engine problem? No power pulling out from stop randomly.

[ben@speedbarn]

2004 F350 Dually 6.0

Randomly our Dually will fall on it's face pulling out from a stop. This happens sometimes when empty, and sometimes with a loaded trailer. It feels like no matter how hard you push the pedal it's not accelerating at all. It may take 200 feet, or a 1/4 mile and then take off like a rocket. Switching between tow/hall, and or shifting from drive,down to 1 does nothing. This has been happening off an on for quite a while, in both winter and summer. And when the truck is first started in the morning, and in the afternoon while the temps are up. It's like it's stuck in 3rd gear or something.

Is that a common problem? I've heard of trannys not upshifting when there is an issue, but not them being stuck in a high gear from a stop.

[Evil Eye]

Sounds like your torque converter isn't locking.

[Arctic Fox]

My '06 F350 SRW used to do the same thing, never did figure out why.
Your right it feels like it's starting out in a higher gear, but could also be the turbo vanes are stuck in the open position causing the turbo to spool up very slow.

[Arctic Fox]

Originally Posted by Evil Eye

Sounds like your torque converter isn't locking.

Torque converter should not lock up until trans has shifted into the higher gears... it would never be locked up when starting out from a stop.

[ben@speedbarn]

OK, I was originally thinking the vanes sticking also. Is there a way to test the controller? The turbo was replaced a year ago, so I'd hope they weren't gummed up yet. It seems as though I should have some power even if the vanes are sticking correct? I'd think even with zero boost I'd still be able to pull out faster than a few miles per hour.

As for the torque converter....

Is it possible that it is locking up in first gear, and not letting the engine build enough rpm?