I have it on my Z4. You can use a 335is modified bin to make it work, but I think @jyamona plans to add this to the MHD flash options in the near future.
Z4 LPFP Sensor Retrofit
- Thread starter Jake@MHD
- Start date
I have it on my Z4. You can use a 335is modified bin to make it work, but I think @jyamona plans to add this to the MHD flash options in the near future.
Ken or @jyamona , who can guide me in the right direction on replacing the bin file? Need someone much more talented than me and willing to pay! Also, Ken, do you have or know where I can find how to wire this to the DME to match the 335s? Sorry for so many questions. Did a bunch of fuel line changes, LP pump upgrade, etc. and the HP is dipping a bit. Want to rule out the LP as the issue before spending a ton on a new pump.
If you pull the wires from a 1 or 3 series junk yard find, you will know which pin and connector as you'll document that when you remove the wires. Off the top of my head I don't have that information and I don't have the time to look it up for you. If you need assistance once you get that installed, you can reach out to me for tuning.
hi, i'm sorry i'm asking a question which is not about the z4.
when should we upgrade the LPFP sensor on 335i n54?
for the moment i have no problem, i will install a walbro 450 in a few months and i will only run on sp95 eur, is there any interest in changing this sensor?
when should we upgrade the LPFP sensor on 335i n54?
for the moment i have no problem, i will install a walbro 450 in a few months and i will only run on sp95 eur, is there any interest in changing this sensor?
If this is an original sensor I would replace it. I have had to replace them on all my N54s at some point.
Replace the LP pressure sensor when it fails. Z4 runs without a LP sensor, so I'm not sure why anyone would think the LP sensor ever needs to be replaced unless it completely fails and you can't see pressure in your logs. I actually installed a sensor on my Z4 so I could see the pressure, but it's not required. Replacing the LP fuel pump is a good thing as most stock e9x LPFPs can't support the fuel lift requirements which leads to rail pressure drop, which is not a good thing.
Just like any other car with a LP sensor. Just need the sensor and harness wires to fish through to the DME and then flip the switch within the ROM to activate it.
I flashed my 335i with the Z4 ROM. Part of the process involved modifying the Z4 calibration to accept the LPFP setup on the 335i so I should be able to alter your Z4 bin to start monitoring the LPFP sensor.
There's several parts to it. You need to set the toggle to enable the LPFP reading, then add the scaling for the sensor. That should let you read the LPFP in MHD.
You could also copy over the logic for LPFP control from the 335i, PID controlled rather than fixed speed. Not sure if it works any better though.
I think you might be over thinking the requirements. The logic should already be there, it just required a switch to turn it on/off like the boost solenoids or secondary o2 sensors for my Z4. At first I loaded the 335is rom on my car to enable this, but I have it working on my Z4 rom with the help of @jyamona who found the logical switch. I'm not aware of any other table logic that needs to be adjusted, but hopefully this mod can be added as a check box function within MHD flash option in the next release so everyone who wants to add this can even with the OTS maps.
Maybe some bins differ but when I tried that toggle from Jake (LC_FUP_EFP_AVL) my car stayed in limp mode. I ported a EU Z4 35is bin to run on my 335i so had to bring across all LPFP and hydraulic steering torque modelling tables.
In my Z4 BIN the sensor scaling table is all 0 so no matter what voltage the sensor was reporting it was always showing a pressure reading of 0. I had to copy the scaling values over from the original IJE0S 335i bin.
To get the LPFP in my 335i to control to the sensor reading I had to bring across the control tables as in the Z4 the logic that controls LPFP is very different. Part of the DME logic is auto sensing so even though the Z4 BIN is flashed the LPFP still expects to see a control signal whereas the Z4 does not.
Maybe someone can correct me if I'm wrong here but is the EFP controlled over CAN on the Z4 and via hardwired connection on the 335i?
In the logic there's two variables for EFP control,
1) Vehicle without EFP-control-unit and
2) Vehicle with EFP-control-unit
The reason for the change was LEVII emissions related, I'm not sure of the full details though, maybe it was a hangover from the MSV80 and all N54s are done via CAN. There's certainly a huge difference in how the LPFP is controlled between the Z4 and 335i though.
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Well, that makes sense. Good information. Maybe Austin & Jake @ MHD can come up with a solution within MHD so others don't have this issue.
I've never seen a clear description of how the EKP/DME handle fuel on the Z4 versus everything else. I assume the LPFP sensor is part of that equation on everything else. To add to this, commonly tuners will say the Z4, stock, can provide more LPFP pressure (like a "stage 2") vs other N54s. Again, never seen an explanation as to the guts of why.
All that said ... not sure if there is a benefit to changing any logic. My simple desire would be to have the LPFP information just from a diagnostic perspective.
Thanks @carabuser for offering to help. Good discussion here.
All that said ... not sure if there is a benefit to changing any logic. My simple desire would be to have the LPFP information just from a diagnostic perspective.
Thanks @carabuser for offering to help. Good discussion here.
I think Jake probably needs a few more samples before implementing anything. Not many Z4 users out there any even fewer interested in retrofitting a low pressure fuel sensor.
I'm eyeing up larger turbos for my Z4 so when that happens I'll probably want to upgrade the LPFP and then add the sensor. Just need to figure out upgraded outlets for the RHD Z4.
I would add the sensor and wire it up but I got no time to mess around with bin changes and searching everything to figure out what to wire where.
On the Z4 the bin changes would just be easier if you just want monitoring only, just a couple of tables. If they aren't present then the car would still run fine.
Once I get chance to check enabling the LPFP sensor on someone else's car then I'll just post a small XDF with the required tables.
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