Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
2010 Mazda Mazdaspeed3
This is the 2.3L turbo version of the Mazda3. The car is heavily modded with a new bigger turbo and built engine internals. Car used to hit boost targets of 21-23psi but currently having a boost issue where it hardly reads any boost. Boost control solenoid/throttle body and anything pretty much obvious has been swapped out at one point. Cat converter is not clogged.
Boost will hit 3..4…5…and then jumps back down to -1 and so on. Car will hit 10/14psi on WOT.
We have done a pressurized boost leak test/Smoke test and confirmed turbo doesn’t have any issues considering it only has maybe 1000 miles on it. EBCS is a 3 port MacValve. Fuel trims/AFRs are normal. Not a tuning issue mainly because it didn’t have this issue previously under the same tune.
I only see two possibilities: There is no high airflow created at all by the turbine or there is no restriction to build up boost pressure. The later typically is caused by any kind of leak within the intake system. Your tests did not reveal a leak. If this is true you then may have a problem with the turbocharger itself.
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
