Z4 LPFP Sensor Retrofit

[Neg89]

To be clear I see seven and eight mention it for connecting lpfp sensor but on the sensor there are three pins which is which and where to put the third one?

 

[fmorelli]

To be clear I see seven and eight mention it for connecting lpfp sensor but on the sensor there are three pins which is which and where to put the third one?

Z4 LPFP Sensor Retrofit

As the title states, is installing and running a LPFP sensor something you Z4 guys would be interested in? I believe I figured out how to get it active on the DME side. Without a sensor, it can only control the LPFP open loop via a hardcoded map based on pump data gathered in testing. Adding...

www.spoolstreet.com

Back in the thread, post #16, looks like 3 to me.

 

[carabuser]

This is the BMW repair manual photo of it and it only looks like 2 wires are connected:

 

[Neg89]

Hey Smart Guys can you tell me where to put the third wire and if I don't need to connect it which two from three total to use?

 

[Darke Peak]

Hi guys so I finally take a look on 335i metal fuel line with sensor the sensor has three pins not two like I originally thought what can you say about this I was thinking that there is only two pins but there is three?

I bought a second hand 335 engine loom and the HPFP feed line with the low pressure sensor. The sensor has 3 wires and I traced them back to the 44-pin DME connector:
Red/black - pin 7
Blue/yellow (changes to a blue wire) - pin 8
Yellow/red - pin 34
Then I see that the answers were encrypted in the previous posts….

Those wiring ports were empty on my DME so I temporarily connected them and tried to read the pressure through MHD logging but it didn’t work. I need to modify the bin file to enable monitoring. The research and learning continues…..

 

[Darke Peak]

Also worth noting for RHD vehicles: the 335 DME is mounted closer to the engine so the whole loom is shorter. If you already have the connectors for the DME end and the sensor end, then you don’t need to buy a loom. I don’t have the connectors so I’ll just remove those wires from the 335 loom, cut them, insert an extra wire section, then run them inside the Z4 loom.

Here’s a picture of the junction box end (mounts under intake manifold) of a RHD 335 loom showing the extra connector and wires for the LPFS. The circled connector is where the blue/yellow sensor wire changes to blue for the DME connection. Just to make it clear: The Z4 doesn’t have the connector at the junction box or the wires to the DME.

 

[Darke Peak]

I found another diagram for 2009 335 that correctly shows the wire to DME pin 8 as blue (instead of blue/yellow). Anyway, the LPFS still connects to pins 7,8 and 34 on the 44 pin connector. Just thought I’d throw it up here for future reference.

 

[Darke Peak]

I meant to include this picture in my earlier post for Neg89’s reference (and anyone that doesn’t have a loom to use the wire colours). There are two types of LPFS used by BMW for the N54, if yours doesn’t look like this then maybe the pinout is different.

 

[Darke Peak]

The two types of LPFS. They both seem to use the same 3 wire connector so it’s probably safe to assume the pinout is the same.

 

[Neg89]

Hi. Can somwone post a pic of BMW oem new type sensor? It have color marks on the top side. I cut off conector to solder the wires,so no cutout for me left.Pretty shure i connected right,but beter to check

 

[Darke Peak]

Hi. Can somwone post a pic of BMW oem new type sensor? It have color marks on the top side. I cut off conector to solder the wires,so no cutout for me left.Pretty shure i connected right,but beter to check

Sorry, this is the best I can offer.

 

[billj457]

I was able to add the sensor and fish the wires to the DME, does anyone have a modified BIN file?

 

[proboner]

If you have a tuner, you should read out to them for it. Otherwise, it sounds like MHD was considering adding this as a switch you could select? I'd ask Jake (the OP of this thread)

 

[billj457]

Thanks, I appreciate the response. I synced up with Jake and was going to wait to get a custom tune (unless it gets added as an OTS flash option)

 

[proboner]

As an update to this thread, I just got this up an running on my Z4. Pulled the wiring from DME -> sensor from a 335i at the JY, bought the hardline and sensor on ebay (although hilariously when I got in there it appears that the previous owner had already installed the 335i hardline and sensor), plugged the connector into the sensor and ran the pins to the DME, flashed a tune from Ken at Wedge... BOOM. Low pressure fuel data logging. Didn't even have to start the car, had the car in "run" and looked at fuel pressure on MHD and it was showing at 68psi.