I have a ctsc aftercooled setup with a 4.25 pulley. It would always boost at 7psi but up until yesterday the gauge wouldn't go over 5psi. What is wrong ? Can anyone help me



Problem fixed - boost gauge hose had a small hole or something in it . Replaced with new line

 

Most likely belt slip for sure, it will only slip at high revs typically around 7500rpm and onwards.

 

How do I know for sure? And how can I fix this? The belt is in very good shape

 

If you have any logging software on an ECU you will tell, or if you closely watch your revs and boost gauge and see where it drops, probably around 7.5-8k - maybe better getting someone else to look at the revs and boost.

My belt was okay and new'ish a while back but became loose -so it does happen, they do have to be tight.

 

Like how tight? Mine Seems pretty tight . My boost won't build higher than 4 doesn't even drop . Do you think it's my gauge ? Vac is at 18 during idle

 

Borrowed a friends boost gauge , it fixed the problem.

I had a auto meter sport comp.