What's your setup? Any other codes in particular aside from the misfire & lean codes? I can definitely see your STFT and Lambda AFR for bank 2 max out right around 4600rpm which, I'm assuming, is when it starts to misfire and throw codes.
Your fuel rail pressure seems to not dip below 1500psi at peak power so I can't say it's your HPFP. Your fuel low pressure was reading 0 psi the whole time when I viewed the graph, that may be something to address so readings for that can be provided in order to make sure there's nothing up with your fuel low pressure system.
At that rate, the only things I can think of for bank 2 is incorrectly-gapped spark plugs, failing upstream and/or downstream O2 sensor, or failing injector(s). There's also the possibility for a failing PCV valve which is known to cause a misfire in bank 2, even a crack in the intake manifold or valve cover somewhere along bank 2, allowing unmetered air passage.
Keep us updated
Your fuel rail pressure seems to not dip below 1500psi at peak power so I can't say it's your HPFP. Your fuel low pressure was reading 0 psi the whole time when I viewed the graph, that may be something to address so readings for that can be provided in order to make sure there's nothing up with your fuel low pressure system.
At that rate, the only things I can think of for bank 2 is incorrectly-gapped spark plugs, failing upstream and/or downstream O2 sensor, or failing injector(s). There's also the possibility for a failing PCV valve which is known to cause a misfire in bank 2, even a crack in the intake manifold or valve cover somewhere along bank 2, allowing unmetered air passage.
Keep us updated
Gents thanks for the time to review the log.
As for set up I’ll just copy some info from my introduction post. Set up below.
MHD Custom tune/ xHP trans tune
•RB Turbo Game Finisher High Flow
•ER Charge pipe w/ HSK SSQV BOV
•VTT Silicone Inlets
•KLFT Air Intake system
•VSRF CL Downpipe
•Fuel It Ethanol Sensor
•Meisterschaft Cat-back Exhaust with actuating flap
•High/Low External PCV Setup with plugged head-ports
•ER Intercooler (FMIC)
•BMP Port injection (750cc Bosch)
•Stage 2+ Walbro 535 LPHP
•Water Methanol Injection
•Motiv Reflex+ controller w/ 0-10 bar pressure sensor
•BMW Index 12 Injectors
•NGK 1-step colder spark plugs
•NXM oil pressure sensor
I’m going to search for some leaks. I’ve triple checked plugs which are basically new. All are gapped at 0.02”.
Something would definitely seem odd if no low pressure fuel … not sure where to start looking into why that’s not logging. I’m also running port injection which should feed fuel…. Wondering if something is happening there?
As for set up I’ll just copy some info from my introduction post. Set up below.
MHD Custom tune/ xHP trans tune
•RB Turbo Game Finisher High Flow
•ER Charge pipe w/ HSK SSQV BOV
•VTT Silicone Inlets
•KLFT Air Intake system
•VSRF CL Downpipe
•Fuel It Ethanol Sensor
•Meisterschaft Cat-back Exhaust with actuating flap
•High/Low External PCV Setup with plugged head-ports
•ER Intercooler (FMIC)
•BMP Port injection (750cc Bosch)
•Stage 2+ Walbro 535 LPHP
•Water Methanol Injection
•Motiv Reflex+ controller w/ 0-10 bar pressure sensor
•BMW Index 12 Injectors
•NGK 1-step colder spark plugs
•NXM oil pressure sensor
I’m going to search for some leaks. I’ve triple checked plugs which are basically new. All are gapped at 0.02”.
Something would definitely seem odd if no low pressure fuel … not sure where to start looking into why that’s not logging. I’m also running port injection which should feed fuel…. Wondering if something is happening there?
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Nice setup. Yeah unless there was a bug when recording that log, there may be a sensor error somewhere for the low pressure system. Your rail pressure seems to be relevant to an N54 pushing some serious power given your setup, so I personally don't think it'd be anything with your port-injection. Wouldn't hurt to re-assess that system though just to eliminate any failing points
Ran the log again today and the same thing ... not recording the low pressure fuel, or the IAT. I'm going to tear down and check the connector on the fuel pressure sensor to make sure it's secured ... if it is, I'll likely replace the sensor... Still can't find any cracks in manifold or leaks in any vac lines, inlets, outlets, etc ... Haven't looked at bank 2 rear O2 sensor yet, but these were also replaced by previous owner....
Current tune (that came with car from previous owner) is set for 22 psi, But the RB turbo Game finishers seem to push a lot of volume. I'm not even pushing this car yet ... just trying to get it sorted first.... all part of the fun.
Current tune (that came with car from previous owner) is set for 22 psi, But the RB turbo Game finishers seem to push a lot of volume. I'm not even pushing this car yet ... just trying to get it sorted first.... all part of the fun.
Of course, you'll get there. The previous owner could've replaced them but sometimes they can prematurely fail again, especially if they're lower quality. If you didn't find any air leaks then the last thing I could really assume is a faulty sensor for bank 2 whether upstream or downstream because of the AFR reading shooting to the moon rather than reading a realistic lean value before it'd actually cut out.
Don't waste your time troubleshooting the low fuel pressure reading, The Z4 doesn't have that sensor.
You can retrofit it, but I wouldn't bother, the rail pressure will dive if the low side is lacking. It does make the troubleshooting a bit harder though.
Looking at your log it seems bank 2 just leans out. Rail pressure is ok, so I would assume there is a problem with the PI as bank 1 seems to go excessively rich. I would start by disabling the PI and seeing if the banks look even.
Also consider just using the Hydra HPFP overdrive and get rid of PI altogether. Makes for a more reliable setup.
You can retrofit it, but I wouldn't bother, the rail pressure will dive if the low side is lacking. It does make the troubleshooting a bit harder though.
Looking at your log it seems bank 2 just leans out. Rail pressure is ok, so I would assume there is a problem with the PI as bank 1 seems to go excessively rich. I would start by disabling the PI and seeing if the banks look even.
Also consider just using the Hydra HPFP overdrive and get rid of PI altogether. Makes for a more reliable setup.
On a second look, bank 2 is probably cutting fuel injection because of the misfire, not the other way around. Add the fuel mode to the logging params rather than the low fuel pressure.
The corrections are quite severe though, all cylinders are getting major corrections. I would take a step back, disable the PI and start the tuning from a lower boost level. The timing already looks really low so I assume you are at 0% Ethanol.
The corrections are quite severe though, all cylinders are getting major corrections. I would take a step back, disable the PI and start the tuning from a lower boost level. The timing already looks really low so I assume you are at 0% Ethanol.
@carabuser- thanks for the feedback.
I do have an added motive 0-10 Psi LP fuel sensor that is connected through the Reflex+. I checked connections and and am questioning the aux port it’s in - on the reflex side there are two ports with blue wires (light and dark) it’s plugged into the connector with the dark blue wire - I tried switching and re-logging but no luck. I’ll trouble shoot it further with ReFlex.
I’ll try disconnecting the port injection and see if that evens out as suggested.
I’d love to better understand your thought process on the cutting of fuel due to the misfire instead of the other way around (learning opportunity for me with reading the log!).
I’ll add the fuel mode in place of the low pressure fuel and repost a log. I had a look at that earlier and I think it’s all in fuel mode 2 if I recall.
Thanks again for the help!
Edit - I do have an ethanol sensor installed and it has been showing in the neighborhood of 5-6%. Running straight 93 pump gas which has a little bit of ethanol (pump says maximum of 10%)
I do have an added motive 0-10 Psi LP fuel sensor that is connected through the Reflex+. I checked connections and and am questioning the aux port it’s in - on the reflex side there are two ports with blue wires (light and dark) it’s plugged into the connector with the dark blue wire - I tried switching and re-logging but no luck. I’ll trouble shoot it further with ReFlex.
I’ll try disconnecting the port injection and see if that evens out as suggested.
I’d love to better understand your thought process on the cutting of fuel due to the misfire instead of the other way around (learning opportunity for me with reading the log!).
I’ll add the fuel mode in place of the low pressure fuel and repost a log. I had a look at that earlier and I think it’s all in fuel mode 2 if I recall.
Thanks again for the help!
Edit - I do have an ethanol sensor installed and it has been showing in the neighborhood of 5-6%. Running straight 93 pump gas which has a little bit of ethanol (pump says maximum of 10%)
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