With or with out a load my truck feels so sluggish starting off. As I am changing gears it seems to take a minute to get going. Boost doesn't build up right away and it just kind of falls on its butt for a second then comes to life with some power. My rail pressure at idle is about 4500, I change the fuel filter everytime I change the oil since it was new. I usually run with the mp8 box, which I notice a difference with out it. When it is stock it has no power at all. I can haul an empty trailer (7000lbs) through downtown on the interstate, and I have to down shift going up and down the slight changes in elevation. So I always run with at least the mp8 just to be able to move around. But even that seems weaker, it doesn't smoke anymore with this upgrade. I have taken it to the dealer twice and they find nothing wrong. No codes, no reason to look further. I have hauled a lot of weight since I have owned it and I wonder if something is just wore out, but I don't know where to look. I am not sure where my rail pressure should be, it idles around 4500 and peakes at about 21000 to 22000. Any help any one can give is much appreciated, if anyone needs more info just ask, I didn't want to get carried away and write a book here.
Thanks

 

Do you have a boost gauge and a EGT gauge.
I wonder if your intercooler has a leak.

 

I do, boost peaks out around 34 to 35 and egt I don't let get over 1100ish. One more note, I purchased the diablo predator program last fall just because I do haul alot of weight and wanted a little extra power. When first installed, the power was incredible. Throttle was so sensitive, I hardly had to even give it any throttle to accelerate. First time I towed with this box I got a check engine light and the code said fuel delivery error. I figured the lift pump wasn't keeping up so I put a raptor fuel pump on but it didn't help. Ever since that day, when I have the diablo on, I can pull a code when towing, even an empty trailer. I no longer have the throttle response that I did when first installing the program and it has just felt weak. I have taken the program off and gone to the dealer to check things over and they don't find anything wrong. I know something is off, because with the factory settings I can't hardly get a load moving. I have to down shift all the time where I didn't have to before. I am just not sure where to look. I don't know if the rail pressure I am seeing is normal or too low. I will check the intercooler just be sure.

 

no odd colored blue/white smoke?

 

No smoke? Check the turbo impeller. Does it run smooth at idle? Maybe you lost an injector.

 

no odd color smoke, it does have a rough idle

 

I bet you have a bad injctor!

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Go to another dealer and have them do a drop test and load test on the injectors they should have spotted that last time!

 

thanks I'll give it a try

 

Since its an 06 they should be about to read the injector rates using there Computer.

 

got a buddy with the same problem... ill pass on the info... thanks guys!