so heres a new one on me, im kinda stumped. when the truck is warming up while driving, say about 120-160 degrees. the boost pressure varies under slow acceleration from say 2-4psi or 4-6psi, usually about 2psi or so. what causes this and is it just my truck or do all 6.5s do it? the truck runs steady boost pressure under acceleration after the truck reaches about 170 degrees. i was thinking that the computer was richening and leaning out the motor but i dunno. i have a turbo master so i know its not that. any thoughts?

 

it could be that your in cold idle higher rpms or you my have smell exhaust leak and as it warm up boost changes could be air filter getting dirty upper intake leaking

what is running at when cold and what run when hot what brand gauge are you running also

 

my e-tork turbo master runs 13-16 cold or hot , im like crazy sounds like a exhaust leak or turbo waste gate might not be sealing or gauge line leak

 

I'm running an auto meter gauge. It pulls the same amount of boost hot or cold. Its almost like it's surgeing but it's a smooth pull. I can hear the turbo go Up and down corresponding with the gauge reading. It's hard to describe I do have an exhaust leak but when it goes back and forth between 2 and 4 it's about a second up to 4 down to 2 like as your readin it. I'm thinking cold Idle coming on and off since u said something. I do have an ses egr code, could the egr have something to do with it? It's not a major thing, the truck runs fine it's just irritating that I can't figure it out

 

i know this is an old one but i finally got it figured out. i put a plate between the egr and the intake plenum to block it off completely. my varying boost levels finally stopped. it makes constant pressure now hot or cold.

 

i owuld just get a turbo-master and throw the vaccum pump in the trash

i changed mine out and it was worth it 110%

 

I already got the turbomaster. Tried taking the vac pump and stuff off but the comp set off codes so I put it back on.

 

all i did with mine was take the back off that looks like an egr valve and right now im running it as an idler