Car bogging randomly with black smoke

G

Gillmon08

Greenie N00B Member
Hello, a little confused with my mazdaspeed 3 so I'm here. I am a little new to data logging and turbo cars. (Always owned old muscle cars).

Car will pull steady and then randomly starts to cut out, can't accelerate through it. This used to only happen at 5,000 rpms but now it is happening around 4,000 as well. Have to let off and come back into it. When this happens black smoke also comes out of the exhaust. I have tried to check for boost leaks and also reflashed the car with Versa Tuner to a stock tune. Car is stock aside from a muffler. Was wondering if anyone with more experience reading logs could notice anything from these.
 

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Post the actual CSV data logs, also for future reference until those hpfp internals are upgraded only run the stock map anything else is a ticking time bomb.

You need to log the following when logging:
Accelerator pedal position,
AFR
Boost
Boost air temp
Calculated load
HPFP actual
Injector duty cycle %
Intake temp
Intake valve adv
Knock Retard
LTFT
Maf Voltage
Mass Airflow
RPM
STFT
Spark Advance
Throttle Position
Vehice Speed
WGDC
 
Black smoke is totally normal. You probably need to get a hpfp upgrade.
 
Awafrican said:
Post the actual CSV data logs, also for future reference until those hpfp internals are upgraded only run the stock map anything else is a ticking time bomb.

You need to log the following when logging:
Accelerator pedal position,
AFR
Boost
Boost air temp
Calculated load
HPFP actual
Injector duty cycle %
Intake temp
Intake valve adv
Knock Retard
LTFT
Maf Voltage
Mass Airflow
RPM
STFT
Spark Advance
Throttle Position
Vehice Speed
WGDC
Click to expand...

Ok, I should be able to take new logs tomorrow afternoon. I’ll post them here after.
 
Gillmon08 said:
Ok, I should be able to take new logs tomorrow afternoon. I’ll post them here after.
Click to expand...
Do you smell any fuel in the engine bay? With age the I Injector seals can fail and leak another common issue is going to be the injectors just get dirty the joys of direct injection. Dirty intake valves also don't help
 
I went and did some logging. I wasn't able to add all the perimeters in versatuner but I got most. It looks like my fuel rail pressure is super low? (No more WOT once I noticed this). This log was a third and partial fourth gear pull. My RPM gauge might be off a little cause on my dash I shifted at redline. The noticeable cutout began roughly around 5100 on my dash. Im wondering if maybe the relief valve is bad? Therefore it can't build pressure?

Yeah I do smell fuel, I haven't noticed any fuel anywhere though. I just replaced the injector seals with the corksport ones maybe 2,000 miles ago though cause one of them was bad and causing a lean knock.
 

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Haven't had a chance to review logs, but yes failed PRV can cause low fuel pressure here's how you test it
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I tested the relief valve with the monitoring and also physically inspected it and didn’t notice anything wrong. The fuel pressure wouldn’t build high enough to even begin to drop off.

I also tested the fuel pressure off the in-tank pump and it only gave 33psi max. So I’m going to swap the fuel pump. If you are able to notice anything else from the logs though that would be great.

The fuel pump shouldn’t cause my fuel trims to be off yeah?
 
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