Low boost and lack of top end power

[bigboy03]

Let me just say that i have used this site to solve and troubleshoot countless problems on my 01 7.3 and am glad there are so many well informed people willing to share their knowledge. I just rebuilt the motor in my truck do to having a broken piston. I put 75hp injectors in, i have an adrenaline hpop, diy intake, 4" exhaust with muffler delete, and an edge evolution. the problem is that even with my edge on extreme i can only hit 18 psi of boost. it takes off descent but then just kind of planes out and doesn't seem to keep pulling hard. i tried unhookin the wastegate and still got 18 max. i already replaced the up pipe gaskets before i pulled the motor out and i can't find any boost leaks at the IC tubes. Could this be my turbo going bad? i've been screwin with this for weeks and can't figure it out so any help would be greatly appriciated

Thanks

[junkinjoe]

did you pull your intercooler pipes off your manifold and do a presure check on the intercooler and the pipes and boots?i usedd some peices of 3" exhaust pipe welded caps on them and put a regulator in one and put 40-45 psi in it then shut the air off and see how fasst the air drops off, if it drops u have a leak,.

[bigboy03]

i did a preesure check on the whole system at the turbo with a homemade rig and the pressure did drop a little but very slow and i think it was mostly coming from the cap that i made. it seemed to hold pressure really well. if i went anything over 25 psi or so it would blow the cap i made off the turbo so i think the sytem is sealed fairly well i just can't build big boost. which i believe is also why i am getting such horrible mileage and such high egt's, which i forgot to mention

[junkinjoe]

well whAT WOULD BE THE CHANCE THAT U MIGHT OF RIPPED A SEAL ON ONE OF THE INJECTORS WHAN INSTALLING THEM, IT ALMOST SOUNDS LIKE ITS OVER FUELING,DID U RUN YOUR PROGRAMER ON THE STOCK POS, JUST TO BREAK THE MOTOR IN???

[bigboy03]

i don't think so. when i was installing them while it was on the stand i was very carefull to make sure they were going in the bores nice and straight and slid right in with a little pressure. i didn't put the programer in till a week ago and i had around 1000 miles on it or so. it had the same problem before i built the motor, it would take off great but just kind of level off and pick up speed very slowly. i didn't have a boost gauge at the time and i just figured maybe the motor was just tired. i bought it about 6 months ago with 160k on it, got it for $6000 cause it had a slight knock which turned out to be the broken piston in the #7 hole. so i just assumed that was probably the major cause of the lack of power but now it seems to be acting the same with the new motor

[Powerstroker7.3Ldiesel]

Did you have anything done to the heads?

[bigboy03]

i was gonna get the heads checked when i had it apart but i snapped the crank in my supercharged mustang which is my only other vehicle so i had to get the truck back together so i had somethin to drive to work. and on the same note when i tore it down everything internally looked brand new still. bearings weren't worn at all, heads were super clean, there was still cross hatching in all the cylinders. so i think the motor probably only had 10k to 15k on it whenever it got repossed and sold to the dealership i bought it from. with the way everything looked inside i figured everything was probably ok minus the broken piston

[bigboy03]

Thanks for the replies so far, but i still can't figure this beast out. i re-worked my homemade boost leak tester and pressured up the system and couldn't find a leak anywhere. even on stock programming i can hit 17-18psi at 1/4 to 1/2 pedal and if i hold it there till 55-60mph the egt's will hit 1400. could my turbo be shot and just can't put up big numbers? whatever it is its killin my mileage and my wallet at $80 bucks a week to fill up(i'm only gettin about 9.5 mpg) any input would be greatly appreciated.

[Powerstroker7.3Ldiesel]

Even tho your heads look good they could have cracks in them you cant see. Id take them off and get them pressure tested.

[Powerstroker7.3Ldiesel]

wait is your turbo stock?