Out of Power on acceleration

[ghalleen]

Recently, my 2003 6.0 F-350 has run out of steam when I try to accelerate. If I gently ease the throttle down 1/3 of the way or so, it runs fine. However, anytime I push it farther, it acts like it has no power at all. In fact, it'll start slowing down if I'm going uphill.

If I put it to the floor, it will slowly accelerate (like 30-60 in 20 minutes). If I take my foot off the pedal and stomp on it again, it'll accelerate almost normally for the first 5-10mph, and then fall flat again.

I changed both fuel filters today, but this didn't make a difference.

The truck has 125,000 miles on it, and had new head gaskets and turbo installed 1-1/2 years ago or so. I'm not seeing any leaks or smoke, and am not hearing any funny noises.

Please help if you have ideas!

[forina]

I've got a 2005 6.0 that does the same thing. If I have just floored it and then let off, when I floor it again it want go. I could hold it for 20 seconds and it will never show any boost at all. It sounds bogged down and like pressure is building up somewhere but it wont go until I let completely off the throttle and try again. Sorry I cant help you, but if you get answers maybe they will be my answers too. Good luck.

[MUDSTROKIN']

ghallen did you drain your water seperator when you changed the filters?

[DuramaxOn40s]

Sounds like a sensor could be bad. Something with boost, or air. Is the truck throwing any codes, check engine lights?

[MUDSTROKIN']

i'd have your VGT system checked out...

[ajpu1983]

Could be weak fuel pump. Check at the test port on the underhood fuel filter or at fuel pump outlet.

[ghalleen]

Originally Posted by MUDSTROKIN'

ghallen did you drain your water seperator when you changed the filters?

I didn't change the filters myself. I had the shop do it, so I assume they did, but I can call them tomorrow to check. If this is easy to access, I'll do it myself to double check.

Gary

[ghalleen]

Originally Posted by DuramaxOn40s

Sounds like a sensor could be bad. Something with boost, or air. Is the truck throwing any codes, check engine lights?

ABS light is on, but that is all. I don't have anything to check codes with. Do you have a recommendation on an inexpensive option? Otherwise, I'm taking it to the shop.

[MUDSTROKIN']

your water seperator is on your fuel filter housing(HFCM) under your cab on the drivers side mounted on the frame rail. on the side facing your tranny you'll see the screw it's about the size of a nickel i guess? you'll need an allen wrench to remove it. i usually just turn it till the water/fuel starts do drain out and don't actually take it all the way out. also i like to let it drain into a clear bottle so i can see how much water was in it.(the water will seperate to the bottom) i'd say let it drain for about 10 - 15 seconds... hope this help ya out!

[ghalleen]

Well, I got the truck fixed today, and thought I'd share the problem with you all.

It turned out that one of the hoses (about 3" in diameter) had developed a small hole, and pressure wasn't allowed to build up. New hose was about $80, plus one hour of labor at my favorite shop. Fixed, and running good as new again!

Gary