AutoEuphoria
Member
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- '08 CPW Mazdaspeed 3
I've been having a lot of issues with my car lately...I don't really know where to look at this point. I've checked the vacuum lines and everything seems to be right (can't find any leaks). The fuel pressure in this log is what really scares me. I'm not sure if the low boost is a function of the low fuel pressure, or if the low fuel pressure is a function of a loss of boost. Any help would be greatly appreciated.
A little hard to read the boost scale...the top number is 15psi. The second from the top is 10psi. Below that is 5psi, and then 0psi. On this log, the boost builds to ~15psi pretty quickly, then gradually falls off to 0-1psi around 4500 RPM
As you can see, I didn't get much KR. AFR was good the whole way. Fuel pressure dropped WAY down, as did boost. This was done in third gear. Again, I can't tell if my fuel pressure is low and that is causing the ECU to drop the boost to stay safe, or if I have a big boost leak somewhere and that is causing the ECU to compensate by lowering the fuel pressure. I do have upgraded fuel pump internals, but I was never seeing pressures this low before. I was, however, running a MAP clamp and MBC before, so I am not sure how that "tricked" the ECU.
Current mods:
- CAI
- Catless DP
- Catless MP
- silicone boost tubes
- turbo inlet pipe

A little hard to read the boost scale...the top number is 15psi. The second from the top is 10psi. Below that is 5psi, and then 0psi. On this log, the boost builds to ~15psi pretty quickly, then gradually falls off to 0-1psi around 4500 RPM
As you can see, I didn't get much KR. AFR was good the whole way. Fuel pressure dropped WAY down, as did boost. This was done in third gear. Again, I can't tell if my fuel pressure is low and that is causing the ECU to drop the boost to stay safe, or if I have a big boost leak somewhere and that is causing the ECU to compensate by lowering the fuel pressure. I do have upgraded fuel pump internals, but I was never seeing pressures this low before. I was, however, running a MAP clamp and MBC before, so I am not sure how that "tricked" the ECU.
Current mods:
- CAI
- Catless DP
- Catless MP
- silicone boost tubes
- turbo inlet pipe
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