As the title states sometimes when i take my car out and boost it once i hit 4500 rpm the boost goes for 10 psi to 5 psi. Other times it boosts just fine. I've been reading up on what it could be but what I dont understand is why it only happens sometimes.

 

Sounds like check valves to me

Dennis,

 

Yep if you can get full secondary boost with a quick lift and stab on the gas then you probably have a bad check valve going to the pressure tank or vac tank.

 

Andrew, we have some viton check valves at the garage... for a price

 

haha yeah ill talk to Dan about it and see what he's says since your living it up in Las Vegas now. I hate you...