BMW M5 Forum and M6 Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter #1
I have an s62 in my touring and am working on the finishing touches with it. Currently dealing with the fuel system. I didn't realize the s62 runs a higher fuel pressure so I'm working on that specifically right now, and I finally have the full understanding of my fuel filter situation. I ordered an m5 fuel filter and was on the way to swapping it with my 540 one. The m5 has threads on the exit while the 540 is hose and clamped, and has the 'standard' pressure regulator that is replaceable. Pretty sure I'm just going to swap the 540 pressure regulator to a 5 bar one and be done with that part of the swap. Otherwise I'm left trying to adapt hose to threads...

Also in the process of getting my fuel pump pulled for a walbro 255hp. Still need to order that stuff.
 

·
Registered
Joined
·
10,197 Posts
Not sure there is a question here, but still the answer is you must use the whole M5 fuel deliver system and don't forget the vacuum line and fuel pump relay. The relay is different and so is the wiring to the relay. There is an added wire from the computer to the relay to control it under low rpm. You need all that for the proper fuel pressure at idle and even so under 2000 rpm.
Your 540 pump could work if you have the rest but will be at its max all the time.
 

·
Registered
Joined
·
34 Posts
Discussion Starter #3
currently the car does run, with all the 540 stuff. I have put probably 700 miles on it. Which vacuum line can't I forget?
 

·
Registered
Joined
·
10,197 Posts
Vacuum line that runs to the M5 fuel pressure reg. That plus the correct fuel pump relay control(reduce) fuel pressure at low RPM. Without those, the fuel trims get a 6 letter word beginning with F. The same 6 letters can effectively make a mess of your trims thru the full range, but mainly at low RPM. If things are perfect then this may go unnoticed, but if something goes a miss (vac leak) it maybe impossible to diagnose due to the built in errors you have created. Only because the M5 ecm is so adaptive.
 

·
Registered
Joined
·
128 Posts
I just did all this on my e38. The regulator swaps right over, the vacuum line is already there for the 540. The pump motor, take the inlet sock off, pull the 2 wires and hose. The pump is a bit difficult to get out of the holder, just don't break the plastic retainers. The motors are physically the same size.
The relay module, on mine anyways the DME wire needed to be moved to a different pin and a ground wire was added.


Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
1,433 Posts
I just did all this on my e38. The regulator swaps right over, the vacuum line is already there for the 540. The pump motor, take the inlet sock off, pull the 2 wires and hose. The pump is a bit difficult to get out of the holder, just don't break the plastic retainers. The motors are physically the same size.
The relay module, on mine anyways the DME wire needed to be moved to a different pin and a ground wire was added.


Sent from AutoGuide.com Free App
The euro models of M5 use the same relay that the 540i uses here, so I don't think it will affect it too much if you don't switch it out, but it will have an error code unless you flash euro software. I changed mine out for the relay module since it was only $30 for the module and I used a couple wires I had left over from the swap to put in the relay socket. One of the wires was run to a ground point in the c-pillar on the passenger side. If you do go with the Walbro 255lph pump, it will fit with the foam sleeve around it that is mentioned in one of the threads on this forum. You'll need to splice the wires to a pigtail that is also mentioned. If you use the M5's pump like Trevor did, there is no splicing involved. To swap the regulator like Trevor did, you just need a pair of snap ring pliers. connect everything else just the same as it was. That's it.
 

·
Registered
Joined
·
34 Posts
Discussion Starter #8 (Edited)
heres a copy/paste update for the pump. Going to order the m5 regulator and run the 540 filter. I think I'll skip the fuel relay/module and just run the 540 one.

got the pump installed. Ended up being a sweet pump as per internetz, Deatsch werks subie drop in. DW300 or something. Pushes 290 LPH at 70 psi, plenty for my stock and even a fairly modified one.

Need to order m5 fuel pressure regulator to finish the fuel system.

stock


looking at how I'm going to do this


should work


soldered and done. Install wasn't as nice as stock because the outlet is straight up vs 90 degrees on the stock pump. The vertical outlet of this pump proved to be an issue, but nothing that required force to overcome when putting the cover on the tank.
 
1 - 8 of 8 Posts
Top