N54 Need advice to add 2nd pump to my Stage 2 fuel set-up

Dumaurier7

Sergeant
May 19, 2020
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0
Both MHD and BootMod have their own as well as the Zetronix controller which I know is supported by MHD and Ecutek.
 
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JonEQuest

Private
Nov 7, 2018
39
16
0
Kenner Louisiana USA
Ride
2008 335i Convertible
I figured I should show what I ended up doing. I went back in with my old bucket that cut the bottom out of, (luckily I saved it). It was tight but both pumps are in and I also changed the filter and regulator at the same time since I accidentally broke the retainer clip on the filter top hat anyway. I have the second Walbro 450 on a relay that will be triggered from the BMS controller since it has an output for it.
 

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turbohugh

Private
Nov 13, 2018
47
11
0
Ride
E92 335
I figured I should show what I ended up doing. I went back in with my old bucket that cut the bottom out of, (luckily I saved it). It was tight but both pumps are in and I also changed the filter and regulator at the same time since I accidentally broke the retainer clip on the filter top hat anyway. I have the second Walbro 450 on a relay that will be triggered from the BMS controller since it has an output for it.
Im not sure if that 'rubber' looking hose in the tank will hold up very long. PTFE hoses are pretty much the only thing that wont degrade in the tank , but yMMV .
 

turbohugh

Private
Nov 13, 2018
47
11
0
Ride
E92 335
Curious what you used to seal the bolts in the top hat.
If it's like the kit I have, you drill the bolt hole undersized, and run a tap [that's what I did]. The top hat is plastic and seals well with washers . There's no real pressure there so I've gotten a tight leak free seal just with sealing washers on the top side. I imagine if it doesn't seal evap leaks would happen. YMMV.
 

JonEQuest

Private
Nov 7, 2018
39
16
0
Kenner Louisiana USA
Ride
2008 335i Convertible
To answer the questions. I was also baffled as how to seal the bolts through the hat but realized as "turbohugh" said there is not much pressure at all and I drilled them just big enough where the bolts had to crew through the plastic. I also have washers on both sides and the first nut is to hold the screws tight with a second nut for the wiring ring terminal.
As for the hose, I used fuel injection rated hose so it should hold up. Some kits come with similar rubber hoses and people who have gone from stage 2 to 3 or 4 report the hoses were still holding up when they pulled the pump out a year or more later. Since I replaced the fuel filter/regulator assy. I now have a lot of that flexible plastic hose in my spare parts bin. If I ever pull the pumps again, I may swap out both of the lines to longer ones using that line so it is easier to get everything abck in the tank. Right now it is tight and kind of a pain.

P.S. My fuel pressure (according to JB4 display) is about 63-65 for LPFP and sits at 5 for the HPFP at idle. The HPFP goes up to 13 or 14 peak when under heavy load. From what I havd read that should be pretty normal.

ADVICE WELCOME: One thing I have noticed is that since adding the whole PI setup with larger fuel line, etc. I get the "2AAF Fuel Pump Plausibility" error code often now. I have not tuned anything special for my PI yet except changing a JB4 setting from 0 to 99 to activate the BMS controller. I have the secondary fuel pump triggered off of the BMS controller. I added "Fuel Enrichment" gauge to my JB4 display and under boost I do see the fuel enrichment kick in. Maybe the "plausibility" code is the secondary fuel pump kicking in late? Not sure, but I am not going to do any hard WOT pulls until I get some tuning done.
F.Y.I. I am running pump 93 on JB4 map 5 "autotune".
 

JonEQuest

Private
Nov 7, 2018
39
16
0
Kenner Louisiana USA
Ride
2008 335i Convertible
I'm also running BMP4 with PFS Bucketed stage 3. I think my BMP4 is running my pumps in parallel. Hopefully you copied your config file from the BMP4. When I ordered it I specified 2 pumps, and it seems wired to drive them parallel. I never get the 2aaf code [not even shadow code anymore], but It was a constant annoyance before going BMP. I'm on MHD , I wonder if that's a difference. I'm also on MSD80 computer . Have you used the BMP torqbyte software to log the EKP / BMP performance, specifically requested duty cycle vs actual ?
I didn't do any kind of software updates. I don't know what a bmp4 is. My second pump runs off a relay that is triggered by my BMS injector controller. Actually I haven't seen the 2AAF code as often lately.
 

turbohugh

Private
Nov 13, 2018
47
11
0
Ride
E92 335
I didn't do any kind of software updates. I don't know what a bmp4 is. My second pump runs off a relay that is triggered by my BMS injector controller. Actually I haven't seen the 2AAF code as often lately.
Sorry I miss-read BMS as BMP lol.. sounds like your setup may be working for you. Cheers !