Something maybe wrong with your HPFP. I'm not familiar with the ODB Fusion app, but on the Cobb AP, I see pressures upward of 1000PSI when cranking and starting the engine.
I've had my fair share of no starts on my Speed3 haha. Firstly, check actual HPFP pressures if you have an accessport installed. It should be right around 50-60 PSI iirc when the key is turned to the on position. When cranking, that pressure should go up a lot. After cranking, the pressure...
Before you go ahead and purchase the CST4, get your FMIC situation sorted out first. Reason I say this is because I own a CST4 and wanted to go with an under mounted FMIC piping kit, but unfortunately, the CST4 is not clockable (At least not with a decent amount of modifcation). Otherwise, FMIC...
Here is my build log of my 08 Mazdaspeed3.
History:
I purchased the car back in 2017, with the previous owner having done lots of mods to it already. I previously owned a regular 05 Mazda3, and wanted something faster. This vehicle has been my first experience with any kinda forced induction...