no power dt 466e

help!, please!!! 466e problems can someone shed some light on my problem? i bought a  2001 4900 ramp with only 17,000 documented miles it,s like brand new the thing is the truck sat in a heated garage for 9 years not run at all  when i bought it 9 months ago something didn,t sound right but i thought it must be something simple and bought it anyway...it had a slight vibration and seamed to be a little sluggish .. well as time has gone on  the problem has gotten much wosrse...i brought it to international and because there are no codes present they refuse to think there is a problem or they do not know the problem.. they would not even give it the buzz test... they were so adiment that the truck was fine they took it for a test drive and charged me 600.00  they are no help!!.what is happening is the truck has a terrible vibration.and it has great difficulty excelerating enough to make the auto trans. shift properly it always shifts but not smooth because the rpms are so hard to get up to proper speed    now in the morning the truck starts right up... and it allways does...it will run like brand new but that only lasts for about 4 or 5 minutes... then it starts to vibrate almost to the point that it sounds  as if it was terribly out of time...very hard to excellerate it feels as though something is holding the truck back.. i have changed the  transfer pump, fuel presure is fine ,changed high pressure pump on the advise of someone  it did nothing. changed cam censer no help,it has now gotten to the point the i can almost not drive the truck...the strange thing is if i shut the truck off for 5 minutes and get a coffie. i start it up and it takes off like brand new shifts exellent it has so much power it pins me in the seat... that lasts about 1 minute and then right back to no power, bogs down when i excellerate.  the motor runs so rough it shakes the whole truck you can hear the motor rapping at idle because it is running like it,s out of time. i know the timing is preset my buddy has the same motor his idles nice... sounds like a sewing machine mine rocks and bangs it,s fighting itself to stay running it has so much compresion it runs but some of the cylinders are not firing properly.  my theary is, either i have some bad injectors or possibly a bad ecm both are very expensive.   will the buzz test tell me if the injectors are bad even if there are no codes prssent the thing that kills me is how can it run so good when i shut it off for 5 min. and then right back to no power any sugestions any one???another thing it does is lets say i,m on the highway and i take an off ramp i go from 55 mph to ten then go to take off again, i can put it to the floor and nothing it just bogs until all the fuel clears or something... then i can slowly build up speed its like its fooding out when i go from fast to slow and then try to go again its horrible, a new motor that runs like it has 500,000 miles on it.someone please make some sugestions thank,s phil any input would be apreciated i have spent about 4500.00on parts and labor paying people to take it on test drives and guessing what is wrong only international  has the computers to diagnose it properly and they wont do it god forbid they admit they missed something 9 months ago when i first brought it in. the wise guy at the dealership told me to drive it until it is broken! well now it is just about broken i,m killing my new motor and probably my 3000 allison transmission that i searched hard to find ...i spent 35,000 dollors all the money i had saved and now my truck is just about done at 30,000 miles i am going to loose everything if i do not get my truck back to work any body got any ideas??? thank you