dumping boost at part throttle help

[grayson496]

Hi guys im new here. I have a 99 f350 with full 4 inch mbrp and a air intake system. Has the edge programmer which i swithed back to stock tune since till I fix the problem. At part throttle it sounds to me like its dumping boost from 5% to 30% throttle. Hear a bunch of air, but if I go to mid throttle or let of throttle completly it snaps out of it. I was lisening to the exhaust last nite and i noticed it go quiet then you could hear the turbine spinning then quiet. goes back in forth. Im assuming the waste gate is acting up but i dont know why? Im mechanicly inclined. Went to school for it but it wasnt for diesel mech.lol. I dont know how the 7.3s waste gates are setup. ecm controls them i assume. Any insight would be great guys. There is not a decent diesel tech around my area. Merry Chrismas to all thanks

[crf250guy]

Sounds like it could be your exhaust back pressure valve closing. Did it start doing this when it got cold out?

[rosski423]

mine is the same way, how do you fix that problem with the ebpv?

[crf250guy]

Its actually normal operation, if the engine cannot maintain temperature. It will actuate at idle or at cruise under low load. There are threads on here that describe how to disable the ebpv, but the result may be a cold cab in cold weather. I personally enjoy a warm truck when its freezing out