Boost Gauge reading 15psi on stock boost

[sandspeed]

i cant wait to get forged internals and boost 15psi everyday

 

[Alejo_NIN]

i hope not!!!!

i'm getting boost happy

 

[Drumfreak]

When the car is off where does the needle sit? Had a defective SW gauge when the car was off it read -3 vac and under WOT it read only 3 to 4 psi.

 

[Alejo_NIN]

it was brand new, i returned it already...but it read ZERO....also, i hade a 20 vac....which is what ppl usually run...
when accelerating, it will go to 5, then 7 then 11 and finally get stuck on 15
it will even bounce at 15....just like when you rev your engine and it fules cuts...the way the needle moves

 

[BRICE]

It happened to a guy in Canada... Mazda still looking for the awnswer... Manifold maybe

 

[GreySpeed]

That same thing happened to me. I thought it was the gauge at first as it still read vacuum corrrectly, turned out the wastegate actuator was finished. To test it, disconnect the vacuum line at the tee going to the wastegate actuator and blow into the vacuum line. If you are able to blow through with no resistance, then there is a hole in the wastegate actuator diaphram. You'll have to replace it.