[controllerplus]

Long story short, we did a pure stage 2 build with port injection on my f30 335i. Driving it home the car shut off with two codes:

11A401
11B401

Thought it was the HPFP. Replaced that. Same issue. Looked at the EKP, didnt notice any damage to the board but did realize the lpfp did not sound right. Priming wise. Looked at the stage 2 LPFP and found one of the lines blew, we replaced it with my stock one and the car fired up and ran beautifully with 0 codes at all. It was great.

Come today, we decided to replace the lines on the stage 2 LPFP so I could enable the port injection. Replaced the lines with oem spec parts, put the lpfp in.. nothing. We thought maybe the pumps dead.. put the known working stock LPFP in again... NOTHING. The car just cranks. Same codes as before. This pump was working minutes before installing the stage 2 LPFP.. and now the stock one doesn't even want to prime or function at all. Our rail pressure is 60.. it's just all wrong.

What in the world is happening? No LPFP is working, we verified the pumps function as they should and the car was running PERFECTLY with the stock LPFP MINUTES before installation.

I'm about to sell the car because I'm so sick of this... what in the actual f#$% is happening? It literally makes no sense.

Thank you.

[harkes]

Battery disconnected during the whole process?

[controllerplus]

Originally Posted by harkes

Battery disconnected during the whole process?

yes

[JaredG_F30]

Time to do some systematic troubleshooting. The good news is you know the HPFP isn't getting fuel which is causing your codes. Now you just need to work backward. Do you have a benctop power supply and multi-meter? If so you can test the LPFP on the bench. You'll need to find a wiring diagram or pinout schematic for the pump. Find power (it's probably 12 VDC) and ground pins. Connect the power and ground pins to the appropriate leads on the power supply and see if the pump powers on. If so you know the pump is good and you have an issue with power supply from the car or signal. Again you'll need a wiring diagram of the cable harness to the pump, use your multi-meter to check for power and signal. If you have power and signal from the wiring harness then you have a connection issue. If you don't then you'll need to probe the EKP to make sure you have the right power and signal voltages out of the EKP. Just keep working back until you find the faulty component or damaged wire. It's not rocket science, just takes patience and a systematic approach.

[Eschmacher]

Considering the upgraded lpfp draws more current than the stock one, I would bet on the ekp or the wiring from the ekp to the pump being the issue. But Jared is right, you need to start checking electrical continuity. But if I were you, I'd start by taking a multimeter to the plug going into the lpfp.

[1QuikWS6]

Anyone upgrading their LPFP really should be using the EOSpeed BPM4 by Torqbyte EKP replacement to avoid the stock EKP meltdown issues

https://www.eospeed.com/products/bpm...21178983481426

You can bite the bullet & pay the $699 now - or set along side of road later...

[JaredG_F30]

Just another reason in my book to upgrade the HPFP and leave the LPFP alone.

Originally Posted by 1QuikWS6

Anyone upgrading their LPFP really should be using the EOSpeed BPM4 by Torqbyte EKP replacement to avoid the stock EKP meltdown issues

https://www.eospeed.com/products/bpm...21178983481426

You can bite the bullet & pay the $699 now - or set along side of road later...

[KeatonK]

I have a fuel it stage 2 pump and I just had this exact issue a week ago. Car would not start for 5 minutes after the I got the code. If that is the case it is more than likely the ekps. Replaced mine and car has been running great. The shop that worked on my car said they get hot with the stage 2 pumps and shut down. I have 73,000 on my car and have had the stage 2 pump for around 10k miles. Hoping this one lasts longer

[zole2112]

The fact that you have the OEM fuel pump which was working and the new pump and neither now work points to something other then the fuel pumps themselves. EKP does sound like the culprit since you already replaced your HPFP.
I recently replaced my HPFP, I got codes 110001, 11A002, 11A031. I swapped out my stage 2 LPFP for the OEM and still got the codes a day later. I replaced my HPFP and that fixed it. My next step, if necessary, was to change out my EKP.

[Munchi435i]

Originally Posted by controllerplus

Long story short, we did a pure stage 2 build with port injection on my f30 335i. Driving it home the car shut off with two codes:

11A401
11B401

Thought it was the HPFP. Replaced that. Same issue. Looked at the EKP, didnt notice any damage to the board but did realize the lpfp did not sound right. Priming wise. Looked at the stage 2 LPFP and found one of the lines blew, we replaced it with my stock one and the car fired up and ran beautifully with 0 codes at all. It was great.

Come today, we decided to replace the lines on the stage 2 LPFP so I could enable the port injection. Replaced the lines with oem spec parts, put the lpfp in.. nothing. We thought maybe the pumps dead.. put the known working stock LPFP in again... NOTHING. The car just cranks. Same codes as before. This pump was working minutes before installing the stage 2 LPFP.. and now the stock one doesn't even want to prime or function at all. Our rail pressure is 60.. it's just all wrong.

What in the world is happening? No LPFP is working, we verified the pumps function as they should and the car was running PERFECTLY with the stock LPFP MINUTES before installation.

I'm about to sell the car because I'm so sick of this... what in the actual f#$% is happening? It literally makes no sense.

Thank you.

Did you every get this resolved?