post #46 it is the plumbing, not the wiring causing your problem, every time you have less than 1/4 tank, your left pump is running dry
cheers, Alan
1/4 mile-12.92 @ 108.64mph-NA 3.0L m3 daily driver
I run a stock pump on the driver's side that dumps fuel into the passenger side, then run the passenger side pump to the fuel rail. I still have the fuel rail return running into the driver's side of the tank (like stock). That pump is still running fine, and I drive daily. I've run down to 1.3 liters left in the tank MANY times in the last year with no failures.
I did have a GSS340 fail on my 3.2L. Pressure would die off at high load/RPM. I put a stock E36 pump in there for now, but you really need a high quality pump to turn out 5 bar. I don't think the Walbros are good enough to run 5 bar on the 3.2L for long. Mine started to go bad in less than 2 years. Going with a big Bosch pump next time.
Last edited by JamesM3M5; 11-13-2009 at 01:55 PM.
James Muskopf
RRT Racing
DC Metro's premier BMW service and racing facility
my understanding is you need a high pressure AND high flow pump.
cheers, Alan
1/4 mile-12.92 @ 108.64mph-NA 3.0L m3 daily driver
James Muskopf
RRT Racing
DC Metro's premier BMW service and racing facility
Ok, I want to make sure I understand you guys correctly. I'm showing my current fuel pump plumbing.....both feed and return lines are T'd to both fuel pump fittings. (see photos below, left side 1st then right side 2nd).
So I'm going to have all fuel return going ONLY to the left pump, the left pump feeds the right pump, and the right pump feeds the fuel rail? Correct? And I won't have any unused nipples, right?
My current left side pump plumbing: (big red line is return)
Current right side plumbing:
correct, you no longer use the tees, all return fuel to left pump, pressure from left pump goes to fuel return nipple on right pump, pressure from right pump to fuel rail
cheers, Alan
1/4 mile-12.92 @ 108.64mph-NA 3.0L m3 daily driver
thanks. got it done, will be at the track in 2 weeks, I'll see how it holds up. Hopefully no more blown fuses, and no more fuel starvation.
you won't have any trouble with that setup, unless one of your pumps is no good
cheers, Alan
1/4 mile-12.92 @ 108.64mph-NA 3.0L m3 daily driver
just an update on this mod based on my track day last week:
no more blown fuses, but the car still seems to experience fuel starvation under heavy cornering with less than 1/4 tank of fuel.
hmmmm....
1) I "T"-d the return to bath both pumps with fuel so that they stay cooler.
2) I made extra certain that the siphon portion of the original system was still intact and functioning, not "out of place". This seems to help considerably, and I can run pretty dry without starvation.
3) I do have foam packed tightly on the passenger side to avoid sloshing around.
4) I have foam on the driver side as well.
I'm not sure how much difference the foam makes. Do this at your own risk.
Alex Lipowich
xyobgyn on AOL
Trying to make the world a better place with 5 extra throttle bodies at a time.
Okay so I read the entire post and did a few searches. Just want to make sure I am getting the right part.
My car is a Euro spec (non converted) 98 M3. So it came with the 5 bar pump which I need to replace. I dont want to shell out $600 for a factory pump and came across this thread.
Questions:
1) The housing is pretty much the same between the US and Euro spec cars its just the fuel pump itself which is different right?
2) I will be getting the GSS340 pump from Apeusa. There are 8 different kits for this pump. Which one do I need? http://www.apeusa.com/html/kits.html
Thank you in advance.
Regards,
Lutfy
they didn't have all those options when I bought my pumps.
I believe kit 37 most closely resembles what you will need, but you will also need a thin foam spacer for each pump in order to make it fit the pump housing.
EDITED ....see below....
bumping this back up to the top because I need help again.
I have two Walbro GSS340 fuel pumps in the stock E36 fuel tank. Each has it's own circuit and fuse (they are split after the fuel pump relay). The motor is a stock S50B32 (no cams, only Group N software flash with 8K redline)
I revised the plumbing as described in my post #56 above. Fuel return goes only to left side pump, L pump feeds R pump, then R pump feeds fuel rail.
I keep having fuel starvation and blowing fuses below half tank of fuel on a specific hard right-hand, uphill turn at my local track. so it cannot be the L side fuel pump running dry. It must be the R side, as the fuel is sloshing away from this pump in the corner. At this point my only option is to fill the fuel tank nearly full, but this is not ideal from a weight standpoint. And there's the problem of fuel spill through the vent too. EDIT.....after exposing all the wiring, I found it IS the LEFT pump that keeps blowing fuses. Now I'm really confused!!
Is the right side running hot? Should I 'T' the return line to feed BOTH fuel pumps again? Or 'T' the feed line so that fuel is getting to the rail from BOTH pumps?
Last edited by jmitro; 03-29-2010 at 03:28 AM. Reason: correction
bump
where I can find fuel flow diagram for euro m3 e36 fuel pumps? Is this pumps can have 50 gph at 60 psi?
http://www.youtube.com/watch?v=Ocrvaw3d4UM Dont drive over limited speed!!! Drive safely......
Don't know the gph but the pressure is 5 bar which is about 72psi.
It's not speed that kills, it's the speed difference that does. Obviously you aren't going fast enough.
Turning Benjamins into noise since 1997
I read a list of the 100 things you MUST do before you die. Funny, "Yelling 'HELP'" didn't make the list!
I'm just wondering.
The delivery unit for the S50B32 It seems is now no longer available.
The only option is to swap with an aftermarket pump retaining the original sender unit. Does anybody have a specific recommendation for a replacement pump ?
Has anybody tried a delivery unit from an E46 M3 ?
Will it fit into the E36 tank and will it run at the same required 5 bar pressure ??
I may be off, but it's the pressure regulator not the pump that does that function (pressure regulating).
Coming from a NA delivered car that has a swapped S50B32, it ran for years with the original pump. Eventually, we fitted it with the Bimmerworld twin pump set up.
04M3 TiAg 69k slick-top 3 pedal
99M3 Cosmos 61k S50B32 euro 6Spd
88M3 AW 43k miles Project FS
WTB: 3.5" Eurosport/Conforti CAI
Yes this is correct. The pressure reg does the regulating, but I was informed that the pump must be able to handle the 5 bar required for the S50B32 otherwise it will strain.
I'm in the middle of trying to source a new delivery unit or failing this, a new pump section, so all this is kinda new to me.
We learn as we go I guess.
Bookmarks