Question about boost gauge

onze07

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Mazdaspeed 3
I installed my boost gauge and i was wondering if I did it correctly because it seems to not be working. I hooked my vacuum line through the firewall to the hose which goes from the top of the blow off valve to the engine, but when i push the gas, the gauge only goes from -15 to -10 then doesnt go up anymore. Could this be an electronic issue or an issue with how i hooked the hose up? I have seen people do it this way without issues, but mine is not working :( PLease HElp!
 

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It may be working just fine.
What does it read when you're driving in boost?
It seems to me you are just revving in neutral...boost can't build like that.
 
you probably have a pinched hose somewhere (could be @ the firewall). check your vacuum hose and make sure nothing is kinked.

does the gauge reads zero when you turn the engine off? if not, return it and get a new one.
 
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At idle and under low acceleration it is normal to read around -15 or -10. Reving in neutral will not make boost because the engine needs to be under load for the turbo to build boost. Take it for a drive and give it some gas. If it still doesn't make it into the positive (around 15 under full throttle in the mid-higher rpms) then you may have a leak. But so far what you are saying sounds normal.
 
^^^ - put the engine under load out on the highway at say 60 mph in a gear that has you above 3,000 rpm and got WOT. Look at the gauge. It should quickly move into positive territory and approach 15-16 psi depending on gear and rpm. If it does not do that, let us know and well help you try to figure out whether you have a bad gauge or a leak or crimp or kink in the line.
 
Did you mean to enter it as minus 15 to minus 10? that's Hg not positive boost.
 
I recently installed a defi boost gauge and I see close to 0psi/0 inHg revving in neutral.
BTW, I routed the vacuum line towards the front of the car and placed the boost sensor in that area and routed the wire cleanly around, rather than routing the vacuum line next to the TMIC/intake-inlet area.
 
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