Strange Power Loss Issue-Help?!

[derek witt]

Hi Guys, been fighting an weird issue for a long time without any resolution. Truck in an 07 Harley with 35000miles, stock.

Problem- when towing ( either my 6000lb boat or 9000lb trailer)and under a good load, it is gutless from 1/2 throttle to full throttle. It barely makes a difference between the two, and won't barely pull 60mph even up a moderate grade. When held wide open in this situation, it kind of pulses a couple of hundred rpms and just doesn't make any punch -and on two occasions it stumbled a little until I backed out of it. Also , the fan seems to run alot as well. *Note - Even unloaded it seems a little flat on top, but doesn't nearly show as bad as when towing.

Boost is not a problem it makes 28lbs or so under these situations. ( I checked the cac tubes and hoses to make sure and all is good)

Thought maybe head gaskets, but it isn't puking anything and doesn't smoke anything on startup or show any signs of any leakage.

That leaves fuel delivery. Fuel filters were changed and the problem seems somewhat reduced( maybe just wishful thinking) but certainly still exists. Anybody heard something like perhaps a fuel pump not making enough pressure(?)

Truck has been to dealer twice for this and it throws no codes. They have done the old "replaced egr, everything seems ok, its hard to tell without codes" deal.

Any thoughts from the 6.0 gurus? Thanks, kinda tired at being embarrassed
when pulling my moderate loads and having the Dodge and GM boys blowing by.

[derek witt]

Sorry for the double post guys- can't figure how toremove one. Oops!