3406e low boost intermittent

Hi guys I was wondering if anyone can help out .
I have a 97 Pete with 3406e. At first it was having low power empty going down the road like if there was not enough fuel pressure or no boost at all at all gears and I don’t blow NO smoke At all . It idles fine and I can’t hear a miss in engine neither . I checked turbo.boots, air cooler.I was gonna wait till tomrow to check fuel pressure and swap fuel lines.my boost gauge thing on the diagnostic screen reads 0 boost at all speeds and really sluggish all the time now . So I decided to change boots sensor . I drove it out the yard and was the same for about 1/4 of a mile then out of nowhere started getting 30 pounds of boost and blowing black smoke and plenty of power . The only thing now when I’m coasting down the highway ,and let go off the pedal for
5-10 seconds it cuts off boost to 0 till I let go off pedal and press again then it will grab like normal . Can this be the tps now? Or wiring

 

Sorry last part didn’t make much sense . So when I’m coasting down highway and I let go off pedal for 5-10 seconds and I press pedal again to accelerate, it goes back to being sluggish no smoke no power till I let go off pedal and press it again right way then it will grab boost again and blow black smoke and power like normal .

 

Yea ima have to look at tps more I just kinda glanced at it. And I mean to say the black smoke is good that’s how it was running before I started having this no power no boost problem .when it acts up I don’t see any smoke at all and real sluggish no power .

 

I wouldn’t mind swapping it out . Mechanics prollly gonna charge me the same as if I just go buy it and put it on. I’m just wondering if I have 2 problems now . Tps and boost sensor or if it’s smithing else . Only does it if I let go off the pedal longer than about 7 seconds and it does it all the time no fail

 

I tired pinching the small hose but nothing .

 

Hey guys so I changed boost sensor, tps sensor , and also found this gp sensor behind fuel filter that was broken so I replaced it too.nothing changed except when I first changed the boost sensor it got lots of power and was boosting 30. But the problem now it cuts off power . I think for sure feels like it’s electrical .
Checked all wires on harnes and found few wires that were touching so fixed them.

 

And also before this my truck was governed I’m guessing because I wasn’t going passed 68mhp. After changing boost sensor I got extra power and my truck started going almost 80 . Then it’ll cut out if I don’t press pedal for longer than 10 seconds then I gotta press pedal and let go quick and press again for it to grab again .