2003 6.0 looses power all of a sudden
 

Hello I'm new to the forum wondering if anyone could help me out. my 03 f250 w/6.0 started acting up a bit strange. No major mods other than a straight pipe, air raid intake and a sinister EGR delete kit with valve block off plate. The EGR delete was done approx 8-9 months ago replaced oil cooler and water pump. Truck ran like a champ after these repairs until about a month ago when all of a sudden i started loosing power as if something was holding it back and not letting it get up and go so turbo was dismantled and inspected after thoroughly cleaning and re installing truck seemed to run a bit better but still looses power. The strange thing to me is that truck only does it sometimes cold or warm it doesn't matter its never consistent. I have replaced both fuel filters changed oil and cleaned the air filter out and nothing changes. There is no check engine light and per dealer the only code the truck is getting is EGR related. Dealer suggest i re-install the valve to see what happens but I refuse to since the EGR is not their to begin with and truck ran great for about 10k miles after the EGR was deleted. When i notice the lack of power the truck idles as when the AC goes on and off. Its making me go crazy and no improvement any help on what road I should look toward would be greatly appreciated. Thanks in advance Also I don't get any of the common injector symptoms nor does the truck blow any smoke whatsoever :argh:

First thing I would check is the lift pump. Make sure it has good constant pressure to your Injection pump. Welcome to the forum. It's a good place to find help with problems, an admin will probably move this to the correct section btw.